PS/2 FAQ (frequently asked questions) Last revision date: 21 October 1996 Originally created by Lewis Getschel Revised by Carl Benker (benker@ceco.ceco.com) Gerry Morgan (gerrym@netcom.com) Updated by David Smudski - PC Helpcenter Jeff Holleman - PCCBBS (if you spot any errors, or wish to add anything, please let us know) ============================================================================ Index Section A: Sources of Information and Files; Vendors; Repairs A1. What ftp sites and bulletin boards are available for PS/2 information? A2. How do I obtain a replacement reference diskette? A3. Where can I get the .ADF file for a ???? board? A4. Where can I buy parts/peripherals for my PS/2? A5. Where can I get my PS/2 repaired? Section B: General Architecture B1. What is the difference between ISA and MCA when refering to a motherboard. B2. What are the MCA Specs? B3. Which models of the PS/2 line are Microchannel, and which are not? B4. What processor/speed/bus etc for IBM computers & PS/2's B5. What size cache does the model 77 REALLY have/upgrade to? B6. What kind of UART does a model 50 have? B7. What is a SIMM, and What kind does a PS/2 use? Section C: General Technical C1. What does error number xxxx mean? C2. I used the reference disk while adding a board, but the computer says that no files can be found ( ????.ADF ) C3. I added memory to my machine and now it beeps at me when I start it. C4. Can I abort the memory test at start-up? C5. Does anyone repair PS/2 boards for less than buying a new one? Section D: Upgrades D1. Can a 80286 based PS/2 be upgraded? D2. What can I do to Upgrade a Model 30-286 D3. How much memory can the model 55SX handle D4. What options are there for upgrading the CPU of a PS/2? D5. Who can I call about upgrades for a PS/2 (company phone #'s) D6. What is the Reply motherboard upgrade for the Model 50? D7. Should I upgrade my processor or add memory? Section E: Peripherals E1. What 5.25" drives can be added to my machine E2. What kind of MCA video accelerators/cards are available? E3. What is the special SCSI connector by IBM & how to make one? ============================================================================ Section A: Sources of Information and Files; Vendors; Repairs A1. What ftp sites and bulletin boards and phone numbers are available for PS/2 information? FTP SITES: ftp.pcco.ibm.com (includes reference diskettes for PS/2s) BULLETIN BOARDS: In the US: (919)517-0001 (main IBM bulletin board) In Canada: (905)316-4244 (main IBM bulletin board) In Germany: (07034)15-2160 (main IBM bulletin board) (06031)84-5923 (Mainz BBS) (06966)45-3000 (Frankfurt BBS) PHONE NUMBERS WITH HUMANS ON THE END OF THEM: In the US: 1-800-772-2227 (PS/2 Help Line - no charge for in-warranty support) 1-800-759-6995 (PS/2 motherboard repair) 1-800-426-7049 (IBM Direct - sales) ============================================================================ A2. How do I obtain a replacement reference diskette? You can download a reference diskette from IBM's bulletin boards around the world, or get them via FTP. See the item on IBM bulleting board numbers and FTP sites. The downloaded/FTPed file is in .dsk format, so you'll also have to download LDF.COM, which is the '.dsk' unpacker. You should be able to get reference diskettes from your dealer as well. ============================================================================ A3. Where can I get the .ADF file for a ???? board? Your best bet is to download it from IBM's BBS, or to get it via FTP. See the section on bulletin board numbers and FTP sites. If it is a third-party (non-IBM) board, try contacting the manufacturer of the board. ============================================================================ A4. Where can I buy parts/peripherals for my PS/2? Here are some US sources (see Computer Shopper for more sources): DakTech 1-800-325-3238 Compu-D 1-800-929-9333 Computer Town (415)962-8696 Kingston Technologies 1-800-835-6575 Micro Mart (508)833-2225 Page Computer 1-800-886-0055 Reply 1-800-955-5295 Worldwide Technologies 1-800-457-6937 (MCA cards) Refurbished IBM hardware: Micro Mart (508)833-2225 Midwest Digital (216)487-0783 Solutronix 1-800-875-2580 USA Inc. (516)775-9400 Memory: The Chip Merchant (619)268-4774 Data Memory Systems 1-800-662-7466 H.Co 1-800-726-2477 Micro Mart (508)833-2225 Qement (408)998-5900 ============================================================================ A5. Where can I get my PS/2 repaired? Here are some US sources: PC Cooling Systems 1-800-722-6555 or (619)722-6555 Rogers Specialists 1-800-366-0579 Solutronix 1-800-875-2580 Tuscan Computer Labs (805)255-9543 (peripherals) ============================================================================ Section B: General Architecture B1. What is ISA and MCA when refering to the motherboard design? The book I am NOW referencing is: Chet Heath and Winn L. Rosch (1990) THE MICROCHANNEL ARCHITECTURE HANDBOOK A Brady Book, Distributed by Prentice Hall Trade ISBN 0-13-583493-7 |> |> The bus for the IBM PC and AT is now know as ISA bus, (Industry |> Standard Arch). The problems with the ISA bus and how the PS/2 and |> MCA bus (Micro Channel Arch.) solved them are: |> |> - ISA uses edge triggered interrupts, unable to share interuppts. |> + MCA uses level triggered interrupts, allowing shared interuppts. - Orginial ISA boards used only 10 address lines to decode an I/O device, constraining the ISA bus to 1024 device addresses. Of that the system uses most of the first 256 devices address leaving 768 devices addresses. But each "I/O device" can take three device address for command, status and data, so there is more like a limit of about 256 "I/O devices". + MCA boards are required to use 16 address lines to decocode an I/O devices address, so MCA is capble of 65,536 device addresses. But again the system uses most of the first 256 devices address. This leaves 65,280 device addresses to use. If three device address are used (cmd-status-data), only 21,760 "I/O devices". |> - ISA has noisy signal lines (lack of "good" grounding) which can |> be a source of strange problems. |> + MCA has more ground signals between data, so is less noisy. - ISA is "normally" 8 MHz and can only transfer two bytes every three clock periods, (adr-wait-data) giving a 5.3 Mbytes/sec transfer rate. The ISA bus has been run as fast 12.5 MHz, which will give a 8.3 Mbytes/sec. max. transfer rate. + MCA bus"normally" runs at 10 MHz, but the book "hints" that the bus is not constrained in this and could run at 20 MHz in the future. There are also several `transfer modes' available, burst, streaming and multiplexed streaming I/O transfers as well as a matched memory cycle for CPU r/w that can be implemented. The maximium transfer rates on a 10 MHz MCA bus: 16-bit MCA 32-bit MCA Normal transfers 10MBytes/sec 20 MBytes/sec (adr/data) short Burst and long Streaming transfers 20MBytes/sec 40 MBytes/sec (adr/data data data ..) Multiplex Streaming (not available) 80 MBytes/sec (as above and uses the `idle' adr lines to transfer data as well, for a 64-bit transfer) Matched Memory cycle 21.3 MBytes/sec (matched memory cycle changes the timing of (32 MBytes/sec w/o the MCA bus to 62.5 added wait state nanosec. for a 187.5 at 62.5 Nanosec. 4 byte adr-wait-data and 40 MBytes/sec transfer cycle. This with 50 nanosec is on a 16 MHz model timing) 80 as an example.) |> Also PS/2s also have a Watchdog timer which will cause a NMI and |> will allow the system to recover from program loops and "some" other |> possible causes of system hangs. But the software to do has to be |> available like it is in OS/2. (This feature is not dependent on the |> MCA design) ============================================================================ B2. What are the MCA Specs? Answer: MCA specs: Originator: benker@hp-8.cae.wisc.edu Since there have been so many discussions about all of this, I'm posting the OFFICIAL MCA specs. These are direct from IBM. MCA, as you will notice, has the capability to be faster than even the local bus technologies with a transfer rate of up to 160MB/sec. Hope all of this helps. The basic transfer cycle on the Micro Channel is a minimum of 200 ns (100 ns for the address and 100 ns for the data which results in five million basic transfer cycles per second for a device running in burst mode. As shown in Figure "Basic Data Transfer Mode", a data transfer operation is done in two steps. First the address for the transfer (either I/O adapter or memory location) is selected, then up to four bytes of data is moved across the data buffer. Depending of the width of the data path (8, 16, or 32 bits) the instantaneous data transfer rate on the channel would be 5, 10, or 20MB per second. The matched-memory extension is a modification to the basic data transfer mode, which can improve the data transfer capabilities between the system master and channel-attached memory. When supported, it allows the basic transfer cycle of 200 ns to be reduced. The DMA controller on the system board requires two basic transfer cycles to move either 8 bits or 16 bits of data. It moves the data from the originator to a buffer in the DMA controller and then to the target device or memory location. Because two cycles are used per 8 or 16 bits of data, the data transfer rate for DMA controllers is 2.5MB or 5MB per second. For blocks of sequential data transferred over the Micro Channel, it should not be necessary to specify the address information more than once. Both the source and destination devices should update the address for each cycle by the size of the transferred data. This technique is supported by the Micro Channel and is known as streaming data mode (or streaming data procedure). Using streaming data mode with 32-bit transfer, the effective transfer rate is 40MB per second. The usage of the address and data buses during a data transfer using streaming data procedure is shown in Figure "Streaming Data Mode". When the Micro Channel is running in streaming data mode, the 32 address lines are only used during the first cycle of the transfer. These address lines are therefore available for transfer of an additional four bytes during each following cycle. This mode is called multiplexed streaming data mode and gives an effective width of 64 bits (8 bytes) for each cycle. The resulting effective data rate is 80MB per second. This is shown in Figure "Multiplexed Streaming Data Mode". IBM has also disclosed that upcoming generations of Micro Channel systems may implement a faster basic transfer cycle of 100 ns rather than the current 200 ns. With the current cycle the Micro Channel is able to transfer sequential blocks of data with transfer rates of 20, 40, and 80MB per second. Systems implementing the faster transfer cycle would be able to reach transfer speeds of up to 160MB per second. These rates are essential for advanced function bus masters, which must move large blocks of sequential data. ============================================================================ B3. Which models of the PS/2 line are Microchannel, and which are not? PS/2s with models numbers of 50 and above are Micro Channel Architecture machines. PC bus (8-bit) PS/2s: 25, 30 AT bus (16-bit) PS/2s: 25 286, 25SX, 30 286, 35SX, 40SX, L40SX Micro Channel bus (16-bit) PS/2s: 50, 50Z, N51SX, N51SLC, 55SX, 56SX, 56SLC, 57SX, 57SLC, M57SLC, CL57SX, 65SX Micro Channel bus (32-bit) PS/2s: 70 386, 70 386, P70, P75, 80, 90 XP 486, 95 XP 486 ============================================================================ B4. What processor/speed/bus etc for IBM computers & PS/2's ---------------------------------------------------------------------------- | | Factory | Bus | | BIOS support Model | Processor | set MHz | Type | Class | High Dens | Hard ---------------------------------------------------------------------------- PC | 8088 | 4.77 | PC | PC | no | no Pcjr | 8088 | 4.77 | | | | PC/XT | 8088 | 4.77/10| PC | XT | no | yes PC/286XT | 80286 | 6 | ISA | AT | | yes PC/AT | 80286 | 6/8 | ISA | AT | yes | yes PC/3270 | 8088 | 4.77 | PC | PC | PC-AT/3270 | 80286 | 6 | ISA | AT | PC Portable | 8088 | 4.77 | PC | XT | Pc Convertible | 80c88 | 4.77 | PC | XT Model 25 | 8086 | 8 | PC | XT | no | yes Model 25-286 | 80286 | 10 | ISA | AT Model 30 | 8086 | 8 | ISA | AT | no | yes Model 30-286 | 80286 | 10 | ISA | | yes | yes M0del 35sx | 80386sx | 20 | ISA | | | M0del 40sx | 80386sx | 20 | ISA | | | Model 50 | 80286 | 10 1W | MCA16| | | Model 50Z | 80286 | 10 0W | MCA | | | Model 55sx | 80386sx | 16 | MCA | | | Model 56sx | 80386sx | 20 | MCA | | | Model 56SLC | 80386SLC | 20 | MCA | Model 56SLC2 | 80486SLC2 | 25/50 | MCA | Model 57sx | 80386sx | 20 | MCA | | | Model 57SLC | 80386SLC | 20 | MCA | Model 57SLC2 | 80486SLC2 | 25/50 | MCA | Model 60 | 80286 | 10 1w | MCA | | | Model 65sx | 80386sx | 16 | MCA | | | Model 70 | 80386 | 16 | MCA32| | | Model 70-Axx | 80386 | 25 | MCA | | | Model 70-386 | 80386DX | 16/20/25| MCA | Model 70-486 |i486DX | 33 | MCA | Model P70-386 | 386DX | 20 | MCA | Model P75-486 | 486DX | 33 | MCA | Model 70-Bxx | 80486 | 25 | MCA | | | Model 80-386 | 80386DX | 16/20/25| MCA | | | Model 80 | 80486 | 25 | MCA | | | Model 90 XP 486 | i486sx | 20/25 | MCA | | | Model 90 XP 486 | i486dx | 25/33/50| MCA | | | Model 95 XP 486 | i486sx | 20/25 | MCA | | | Model 95 XP 486 | i486dx | 25/33/50| MCA | | | Model L40SX | 80386 | 20/10/5 | ISA | | | PS/1 | 80286 | 10 | ISA | | | PS/1 | 80386sx | 16 | ISA | | | ============================================================================ B5. What size cache does the model 77 REALLY have/upgrade to? = I've noticed IBM's Model 77 (which I'm interested in) only = has the 8k on-chip cache (486DX2 running 66/33MHz), and = no secondary cache. = = Almost every other 486DX or DX2 I've looked at has at least = a 64k external cache (some have 128k or 256k). Is there a = major performance difference from the added cache, or is = this one of those cases where simplicity (I.e., no external = cache) wins? Different people responded with the following comments... "... you can purchase a 256KB Level 2 cache for the model 77 for $499 education price direct from IBM. The part number is 6451095, available from 1-800-222-7257." "... according to most reviews I have read of 486DX2s an external cache makes a difference in performance for double clocked 486s. And appar- ently the performance hit is quite large." "I find that my M77 works great under OS/2! It is really snappy, even when multitasking several DOS, Windows, and OS/2 stuff all at the same time. The cache seems to be an overrated add-on. I think that just having enough RAM on your machine has more of an effect on it's operation. (Mine currently has 24 Megabytes -- 3 8-Meg SIMMs.) Re- member, too, that the very efficient Microchannel bus is also very fast and very good for multitasking (and busmastering)." Many thanks to all who responded - I think I'll skip the cache chip for now, since it looks like an easy add in later. Too bad the PS/2 help line didn't know that 6451095 would work in a 77 :-( ######### UPDATE ##### UPDATE ###### UPDATE ###### UPDATE ######## === After the last FAQ post, I got the following reply=== The model 77 PS/2 does *NOT* accept the cache module indicated. One respondent to my query thought the cache card would work in the 77, but later printed a retraction. The indicated cache card is for the model 95 only. So the model 77 is stuck with the 8k internal cache and no level 2 cache at all. There is probably a reason why the 77 is restricted in this manner, but I don't know why. Update to B5 (November 1994): The model 77 now comes with 0, 128K, or 256K cache. Another Addition to #21. >I ask recently about the performance of the model 77. It has no L2 cache and >I wondered if this machine was as fast as others. One response I got follows >and states that the interleaving memory on the 77 eliminates the need for >L2 cache. The 486 Chip on native 486 motherboard operates in "burst" mode. When a reference is made to a memory location not in the internal chip cache, the CPU fetches first the word that it needs and then the 3 words around it (16 bytes on a 16 byte boundary). The process begins with a cycle in which the CPU generates the memory address on the bus. The memory controller logic decides if the address is in L2 cache, DRAM, or on the I/O bus, then generates an appropriate number of wait states. At the end of the wait states, the CPU fetches the first word of data from the bus. The memory controller then goes on to generate additional wait states as needed before each of the remaining three words are fetched. When memory is interleaved, the memory controller gains access to 8 bytes of data after the initial waiting period. It can buffer these bytes and immediately start a new request for the other 8 bytes of data while it feeds the first word back to the CPU. A 33/66MHz DX2 has a 33MHz memory bus or 30 nanosecond cycle time. Unfortunately, the response of the memory is not based on the DRAM memory rating but must also include signal propagation through the whole bus. Lets be generous and assume that the memory subsystem could respond in 90 nsec. This is one wait state (1 cycle to present the address, 1 wait state, and the data is available at the end of the third cycle). With interleaving but no L2, the CPU presents the address, skips a wait state, then at the end of the third cycle all hell breaks loose: The memory controller has 8 bytes The first 4 bytes of this data are sent to the CPU The memory controller generates the address of the next 8 bytes In the next cycle, the CPU reads the second word of the first 8 bytes There may now be a second wait state In the last two cycles, the last 8 bytes are read. In a perfect system (with L2 cache and no delay) the data would be presented in 5 cycles (one to present the address, 4 to read the 16 bytes of data). In this system there are two additional cycles (7 instead of 5). Either does better than DRAM without interleaving (4x3=12 cycles). Interleaving applies to the entire memory. L2 only applies to the cache hits. Personally, if I was offered the choice of a machine with a big L2, or a machine with no L2 and interleaving, I would take the latter machine. Of course, both would be best, but money does not grow on trees. It is important, however, to admit that we do not know that the program needs any data other than the 4 bytes it was really trying to reference. Once the burst gets started, it must complete and transfer all 16 bytes into the onboard cache. However, the CPU is only certain to be waiting for the first word before it goes about its business. In this example, the DRAM requres three cycles and L2 requires two cycles. The last part of the lecture is that you can only measure things in cycles. A 486 requires two cycles to get anything from any type of memory. That is just the way the chip is designed. Therefore, a 33 or 33/66MHz chip is going to take 60 nsec to get at memory no matter how fast the L2 is. Whether the L2 SRAM is 20, 15, 10, or even 5 nsec, the CPU will only see it at the end of the second cycle (60 nsec after presenting the address). ============================================================================ B6. What kind of UART does a model 50 have? According to the information in IBM's PS/2 Assistant software, the PS/2 Model 50-021 (not the 50Z) used the 16550 UART and the 50-031 and 50-061 both used the 16550A UART. But someone comments: >My old 50Z doesn't seem to have a 16550A. ============================================================================ B7. What is a SIMM, and what kind do I need for a PS/2? SIMM stands for a Single Inline Memory Module. There are 36 bit SIMMs and 9 bit SIMMs. PS/2 50 or greater use 36 bit SIMMs. (32 data 4 parity). Most clones use nine bit SIMMs( 8 data 1 parity) Most of the time if you try to put a nine bit SIMM in a ps/2 it will not fit. And during the POST it will scream at you with errors. As for the addressing lines, ALL 55sx have 24 address lines giving them total of 16 Meg of DMA. All 55sx's can use 1, 2, or 4 Meg SIMM's. When buying memory from third party vendors make sure you tell them they model number of the computer. The difference between the memory in the back of magazines is the speed at which they operate. No sense in puttting a 70 ns 2 meg simm in a Model 50 Z when it can only use 85 or 80 ns memory. If the memory you have installed is not working right, try one of the these: 1. Boot your reference disk and check to see that it is a 4 Meg SIMM. if not thee is your problem... 2. If it is a 4 meg SIMM, it might be bad, or part of it. All micro channel PS/2 will map out the bad memory, which might be the case. Boot the reference and test the memory. 3. If these both turn out neative and you have tested the complete system with the reference disk, take it in to be serviced. Might even be an engineering change on your model. ============================================================================ Section C: General Technical C1. What does error number ???? mean? CodeºDescriptions --------------------------------------------------------------------------- 01xºUndetermined problem errors 02xºPower supply errors 1xxºSystem Board Errors 101ºSystem Board Error; Interrupt failure 102ºSystem Board Error; Timer failure 103 ºSystem Board Error; Timer Interrupt failure 104ºSystem Board Error; Protected mode failure 105ºSystem Board Error; Last 8042 command not accepted 106 ºSystem Board Error; Converting logic test 107 ºSystem Board Error; Hot Non Maskable Interrupt test 108ºSystem Board Error; Timer bus test 109ºSystem Board Error; Memory select error 110ºPS/2 System Board Error; Parity check error 111ºPS/2 Memory adaptor error 112ºPS/2 MicroChannel arbitration error 113ºPS/2 MicroChannel arbitration error 121ºUnexpected hardware interrupts occured 131ºPC system board cassette port wrap test failure 161ºSystem Options Not Set-(Run SETUP); Dead battery 162ºSystem Options Not Set-(Run SETUP); CMOS checksum/configuration error 163ºTime & Date Not Set-(Run SETUP); Clock not updating 164ºMemory Size Error-(Run SETUP); CMOS setting does not match memory 165ºPS/2 System options not set 166ºPS/2 MicroChannel adapter time-out error 199ºUser indicated INSTALLED DEVICES list is not correct 2xxºMemory (RAM) errors 201 ºMemory test failure, error location will be displayed in hexadecimal 202ºMemory address error, address lines 00-15 203ºMemory address error, address lines 16-23 215ºPS/2 Motherboard memory failure 216ºPS/2 Motherboard memory failure 3xxºKeyboard errors 301ºKeyboard did not respond to software reset or a stuck key failure º was detected. If a stuck key was detected, the scan code for the º key is displayed in hexadecimal. 302ºSystem Unit Keylock is Locked 303ºKeyboard or System Unit Error 304ºKeyboard or System Unit Error; Keyboard clock high 305ºPS/2 Keyboard fuse (on system board) error 4xxºMonochrome Display Adapter (MDA) errors 4xxºPS/2 System board parallel port errors 401ºMonochrome memory test, horizontal sync frequency test, or video º test failure 401ºPS/2 System board parallel port failure 408ºUser indicated display attributes failure 416ºUser indicated character set failure 424ºUser indicated 80x25 mode failure 432ºParallel port test failure; monochrome display adapter 5xxºColor Graphics Adapter (CGA) errors 501ºCGA memory test, horizontal sync frequency test, or video test º failure 508ºUser indicated display attribute failure 516ºUser indicated character set failure 524ºUser indicated 80x25 mode failure 532ºUser indicated 40x25 mode failure 540ºUser indicated 320x200 graphics mode failure 548ºUser indicated 640x200 graphics mode failure 6xxºFloppy drive/adapter errors 601ºFloppy drive/adapter Power On Self Test failure 602ºDrive test failure; disk boot record not valid 606ºDrive changeline function failure; drive error 607ºDisk is write protected; drive error 608ºBad command; drive error 610ºDisk initialization failure; track 0 bad 611 ºTime-out; drive error 612ºBad Controller chip 613ºBad Direct Memory Access; drive error 614ºBad Direct Memory Access; boundary overrun 615 ºBad index timing; drive error 616ºDrive speed error 621 ºBad seek; drive error 622ºBad Cyclic Redundancy Check; drive error 623ºRecord not found; drive error 624ºBad address mark; drive error 625ºBad Controller chip; seek error 626ºDisk data compare error 7xxº8087, 80287 or 80387 math coprocessor errors 9xxºParallel printer adapter errors 901ºParallel printer adapter test failure 10xxºAlternate parallel printer adapter errors 1001ºAlternate parallel printer adapter test failure 11xx Asynchronous communications adapter errors 11xxºPS/2 System board async port errors 1101ºAsynchronous communications adapter test failure 1102ºPS/2 System board async port or serial device error 1106ºPS/2 System board async port or serial device error 1107ºPS/2 System board async port or serial cable error 1108ºPS/2 System board async port or serial device error 1109ºPS/2 System board async port or serial device error 1112ºPS/2 System board async port error 1118ºPS/2 System board async port error 1119ºPS/2 System board async port error 12xxºAlternate asynchronous communications adapter errors 12xxºPS/2 Dual async adapter error 1201ºAlternate asynchronous communications adapter test failure 1202ºPS/2 Dual async adapter or serial device error 1206 1207ºPS/2 Dual async adapter or serial cable error 1208ºPS/2 Dual async adapter or serial device error 1209 1212ºPS/2 Dual async adapter or system board error 1218 1219 1227 1233 1234 13xxºGame control adapter errors 1301ºGame control adapter test failure 1301ºJoy-stick test failure 14xxºMatrix Printer errors 15xxºSynchronous data link control (SDLC) communications adapter errors 1510º8255 port B failure 1511º8255 port A failure 1512º8255 port C failure 1513º8253 timer 1 did not reach terminal count 1514º8253 timer 1 stuck on 1515º8253 timer 0 did not reach terminal count 1516º8253 timer 0 stuck on 1517 8253 timer 2 did not reach terminal count 1518º8253 timer 2 stuck on 1519º8273 port B error 1520º8273 port A error 1521º8273 command/read time-out 1522ºInterrupt level 4 failure 1523ºRing Indicate stuck on 1524 Receive clock stuck on 1525ºTransmit clock stuck on 1526ºTest indicate stuck on 1527ºRing indicate not on 1528 Receive clock not on 1529ºTransmit clock not on 1530ºTest indicate not on 1531ºData set ready not on 1532ºCarrier detect not on 1533ºClear to send not on 1534ºData set ready stuck on 1536ºClear to send stuck on 1537ºLevel 3 interrupt failure 1538ºReceive interrupt results error 1539ºWrap data compare error 1540ºDirect Memory Access channel 1 error 1541ºDirect Memory Access channel 1 error 1542ºError in 8273 error checking or status reporting 1547ºStray interrupt level 4 1548ºStray interrupt level 3 1549ºInterrupt presentation sequence time-out 16xxºDisplay emulation errors (327x, 5520, 525x) 17xxºFixed disk errors 1701ºFixed disk POST error 1702ºFixed disk adapter error 1703ºFixed disk drive error 1704ºFixed disk adapter or drive error 1780ºFixed disk 0 failure 1781ºFixed disk 1 failure 1782ºFixed disk controller failure 1790ºFixed disk 0 error 1791ºFixed disk 1 error 18xxºI/O expansion unit errors 1801ºI/O expansion unit POST error 1810ºEnable/Disable failure 1811ºExtender card wrap test failure; disabled 1812ºHigh order address lines failure; disabled 1813ºWait state failure; disabled 1814ºEnable/Disable could not be set on 1815ºWait state failure; disabled 1816ºExtender card wrap test failure; enabled 1817ºHigh order address lines failure; enabled 1818ºDisable not functioning 1819ºWait request switch not set correctly 1820ºReceiver card wrap test failure 1821ºReceiver high order address lines failure 19xxº3270 PC attachment card errors 20xxºBinary synchronous (BSC) adapter errors 2010º8255 port A failure 2011º8255 port B failure 2012º8255 port C failure 2013º8253 timer 1 did not reach terminal count 2014 8253 timer 1 stuck on 2015º8253 timer 2 did not reach terminal count or timer 2 stuck on 2017º8251 Data set ready failed to come on 2018º8251 Clear to send not sensed 2019º8251 Data set ready stuck on 2020º8251 Clear to send stuck on 2021º8251 hardware reset failure 2022º8251 software reset failure 2023º8251 software "error reset" failure 2024º8251 transmit ready did not come on 2025 8251 receive ready did not come on 2026º8251 could not force "overrun" error status 2027ºInterrupt failure; no timer interrupt 2028ºInterrupt failure; transmit, replace card or planar 2029ºInterrupt failure; transmit, replace card 2030ºInterrupt failure; receive, replace card or planar 2031ºInterrupt failure; receive, replace card 2033ºRing indicate stuck on 2034ºReceive clock stuck on 2035 Transmit clock stuck on 2036 Test indicate stuck on 2037ºRing indicate stuck on 2038ºReceive clock not on 2039ºTransmit clock not on 2040ºTest indicate not on 2041ºData set ready not on 2042ºCarrier detect not on 2043ºClear to send not on 2044ºData set ready stuck on 2045ºCarrier detect stuck on 2046ºClear to send stuck on 2047ºUnexpected transmit interrupt 2048ºUnexpected receive interrupt 2049ºTransmit data did not equal receive data 2050º8251 detected overrun error 2051ºLost data set ready during data wrap 2052ºReceive time-out during data wrap 21xxºAlternate binary synchronous communications adapter errors 2110º8255 port A failure 2111º8255 port B failure 2112º8255 port C failure 2113º8253 timer 1 did not reach terminal count 2114º8253 timer 1 stuck on 2115º8253 timer 2 did not reach terminal count or timer 2 stuck on. 2117º8251 Data set ready failed to come on 2118º8251 Clear to send not sensed 2119º8251 Data set ready stuck on 2120º8251 Clear to send stuck on 2121º8251 hardware reset failure 2122º8251 software reset failure 2123º8251 software "error reset" failure 2124º8251 transmit ready did not come on 2125º8251 receive ready did not come on 2126 8251 could not force "overrun" error status 2127ºInterrupt failure; no timer interrupt 2128ºInterrupt failure; transmit, replace card or planar 2129ºInterrupt failure; transmit, replace card 2130ºInterrupt failure; receive, replace card or planar 2131ºInterrupt failure; receive, replace card 2133ºRing indicate stuck on 2134ºReceive clock stuck on 2135ºTransmit clock stuck on 2136ºTest indicate stuck on 2137ºRing indicate stuck on 2138ºReceive clock not on 2139ºTransmit clock not on 2140ºTest indicate not on 2141ºData set ready not on 2142ºCarrier detect not on 2143ºClear to send not on 2144ºData set ready stuck on 2145ºCarrier detect stuck on 2146ºClear to send stuck on 2147ºUnexpected transmit interrupt 2148ºUnexpected receive interrupt 2149ºTransmit Data did not equal receive data 2150º8251 detected overrun error 2151ºLost data set ready during data wrap 2152ºReceive time-out during data wrap 22xxºCluster adapter errors 24xxºEnhanced Graphics Adapter (EGA) errors 24xxºPS/2 System board Video Graphics Array (VGA) errors 26xxºXT/370 errors 27xxºAT/370 errors 28xxº3278/79 emulation adapter errors 29xxºColor/graphics printer errors 30xx Primary PC Network adapter error 3001ºProcessor test failure 3002ºROM checksum test failure 3003ºUnit ID PROM test failure 3004ºRAM test failure 3005ºHost Interface Controller test failure 3006º+/- 12v test failure 3007 Digital loopback test failure 3008ºHost detected Host Interface Controller failure 3009ºSync failure and no Go bit 3010 Host Interface Controller test OK and no Go bit 3011ºGo bit and no Command 41 3012ºCard not present 3013ºDigital failure; fall through 3015ºAnalog failure 3041ºHot carrier; not this card 3042ºHot carrier; this card! 31xxºSecondary PC Network adapter errors 3101ºProcessor test failure 3102ºROM check test failure 3103ºUnit ID PROM test failure 3104ºRAM test failure 3105ºHost Interface Controller test failure 3106º+/- 12v test failure 3107ºDigital loopback test failure 3108ºHost detected Host Interface Controller failure 3109ºSync failure and no Go bit 3110ºHost Interface Controller test OK and no Go bit 3111ºGo bit and no Command 41 3112ºCard not present 3113ºDigital failure; fall through 3115ºAnalog failure 3141 Hot carrier; not this card 3142ºHot carrier; this card! 33xxºCompact printer errors 36xxºGeneral Purpose Interface Bus (GPIB) adapter errors 38xxºData acquisition adapter errors 39xxºProfessional graphics controller errors 71xx ºVoice communications adapter errors 73xxº3.5" external diskette drive errors 7306ºDisk changeline function failure; track 0 bad 7307 Disk is write protected; drive error 7308ºBad command; drive error 7310ºDisk initialization failure; track 0 bad 7311ºTime-out; drive error 7312ºBad Controller chip 7313ºBad Direct Memory Access; drive error 7314ºBad Direct Memory Access; boundary overrun 7315ºBad index timing; drive error 7316ºDrive speed error 7321ºBad seek; drive error 7322ºBad Cyclic Redundancy Check; drive error 7323ºRecord not found; drive error 7324ºBad address mark; drive error 7325ºBad Controller chip; seek error 74xxºIBM PS/2 Display adapter (VGA card) errors 85xxºIBM Expanded Memory Adapter (XMA) errors 86xxºPS/2 Pointing device errors 8601ºPS/2 Pointing device error 8602ºPS/2 Pointing device error 8603ºPS/2 Pointing device error or System board failure 89xxºMusic feature card errors 100xxºPS/2 Multiprotocol adapter errors 10002ºPS/2 Multiprotocol adapter or serial device error 10006ºPS/2 Multiprotocol adapter or serial device error 10007ºPS/2 Multiprotocol adapter or communications cable error 10008ºPS/2 Multiprotocol adapter or serial device error 10009ºPS/2 Multiprotocol adapter or serial device error 10012ºPS/2 Multiprotocol adapter or system board error. 10018 10019 10042 10056 104xx ºPS/2 ESDI Fixed disk errors 10480ºPS/2 ESDI Fixed disk 0 failure 10481ºPS/2 ESDI Fixed disk 1 failure 10482ºPS/2 ESDI Fixed disk controller failure 10483ºPS/2 ESDI Fixed disk controller failure 10490ºPS/2 ESDI Fixed disk 0 error 10491ºPS/2 ESDI Fixed disk 1 error ============================================================================ C2. I used the reference disk while adding a board, but the computer says that no files can be found ( ????.ADF ) >I have a PS/2 (X) that gives me error 165 on startup (system options not set). >When I take out the IBM 300/1200 Internal Modem/A card, the error goes away. >I used the reference diskette to change configuration but no files could be >found for this option adapter. Answer: Any time you add a board to the PS/2 computer line, you get a disk that contains the configuration data that is need by the reference disk. One of the choices of your reference disk is to copy the files from an options disk (the disk the new board came with). Use this choice with your BACKUP copy of your reference disk). Once the reference disk is updated you can choose the configure option and the machine should re-boot without any error messages. ============================================================================ C3. I added memory to my machine and now it beeps at me when I start it. >I have a PS/2 Model ?? that came with 1MB of memory (four 256K). >I wanted to increase the memory, first to 2 Megs, then to four in a few >months. I bought the 2 Meg expansion kit (30F5360) and am having trouble >with the installation. I put the two SIMMs in slots A and B. The >computer gives me an error message and makes me hit F1 when booted. >Some programs (Windows) seem to recognize the memory while others (Norton >Utilities) do not. Norton told me the CMOS record was invalid. Answer # 2 The key-word here is CMOS memory!ºWhen the pc beeps twice at you and says to press F1 to continue, it also displays an error number (see error codes question). From the description this person gives, it sounds as if they forgot to run the reference disk to up-date the CMOS memory. (CMOS memory, for those who don't know, keeps track of the 'current' configuration of the machine (memory, number and type of disks, monitor type etc). When memory is added, the CMOS MUST BE UPDATED!!!!!). This is a little different than question #1, in this case there isn't any options disk that is needed, the auto-configuration knows what to do. ============================================================================ C4. Can I abort the Memory test at start-up? >I've noticed on many compatibles, you can abort the memory check(or speed >it up) on power up, by pressing ESC. Is there a way to do this on the ps2's? >It sometimes gets annoying, especially when you have like 8 megs, and >when sometimes CTRL ALT DEL doesn't work.... The simple fact of the matter is that aborting the RAM POST is a very bad idea. You should never on any machine abort a RAM test. The reasons? Well, if there would happen to be a bad block of memory, you wouldn't know until you hit it while working....then BLAM there went everything you were doing. Also, on PS/2's, if they find a bad block of memory, they will remap around it. That is one of the primary reasons for having a mandatory RAM POST. Most clones don't remap. They just give an error. ============================================================================ C5. Does anyone repair PS/2 boards for less than buying a new one? 1 person's response is: Solutronix, 7255 Flying Cloud Dr., Eden Prarie, MN 55344; 800-875-2580. They replaced the video driver chip and several "likely to fail" chips. The repair, including shipping, cost $295. All repairs are warranted for six months, even if it is not related to the original fault. anothers was: I personally have had dealings with a company in New Jersey called Micro Exchange. They have always been very professional in all of our transactions. They sell used/demo and some new parts as well as doing repairs. Their warranty and repair offering is very similar to Solutronix. Their address is: 682 Passaic Avenue, Nutley, NJ 07110 (201) 284-1200 FAX (201) 284-1550 In early 1993 IBM introduced the Personal Systems Card Repair service. The number is 800-759-6995, and their address is: IBM Attn: PSCR 11400 Burnet Road Austin, TX 78758-3493 They offer 24-hour and 5-day turn-around service (the difference in price is about $50), and the repairs carry the typical IBM 1-year warranty. Update to this question IBM has a repair facility for its boards. The prices for repair are reasonable -in comparison to the board exchange prices for PS/2 stuff. º Here's the phone number..... 800-759-6995 They'll FAX you a charge sheet if you're interested. ============================================================================ Section D: Upgrades D1. Can a 80286 based PS/2 be upgraded? Upgrades by: * * * Evergreen Technologies Inc. 915 NW 8th Street Corvallis, OR 97330 (800)733-0934 (503)757-0934 Fax (503)757-7350 Processor upgrades (based on TI/Cyrix chips, rather than Intel or IBM) * * * Kingston Technology Corporation 17600 Newhope Street Fountain Valley, CA 92708 (800)835-6575 (714)435-2600 Fax (714)435-2699 Hard disk (DataCard combined hardcard/memory card)upgrades Processor upgrades (MCMaster, SLC/Now!, 486/Now!) (Kingston used to use AMD processors as well. Kingston bought AOX) Memory Third party sources: ºComputer Discount Warehouse (800)326-4CDW ºFirst Source International (800)862-9866 ºmany other places for memory only * * * LCC Pacific (formerly Practical Performance) 55 Oak Court, Suite D-104 Danville, CA 94526 (510)838-2171 Fax (510)838-2475 Processor upgrades (chip replacements and motherboard replacements) * * * Reply Corporation 4435 Fortran Drive San Jose, CA 95134 (800)955-5295 (408)942-4804 Fax (408)942-4897 Processor upgrades Hard disk upgrades * * * Sigma Data Scytheville Row, P.O. Box 1790 New London, NH 03257 (800)446-4525 (603)526-6909 Fax (603)526-6915 Hard disk upgrades (Replacement, co-resident) (55SX solution in works) Processor upgrades (386DX to 486, 286 to 386SX) Memory ============================================================================ D2. What can I do to Upgrade a Model 30-286 > My question about upgrading RAM on an old IBM PS/2 model 30 should > have specified that the machine is a model 30-286. No, this piece of information about the 30-286 only being upgradable to 640K is not at all true. Mine came with 1M, and it is upgradable to 4M on the board. Of course you DO have to buy proprietary memory upgrades that are more expensive than standard SIMMS (I tried SIMMs from an old Sun Sparc and they didn't work, bummer). Anyway, I don't know who you talked to, but you can definitely upgrade, though the 286 is limited in how it can use any memory above 640K. ============================================================================ D3. How much memory can the model 55SX handle without an expansion board (motherboard only). Answer #7 The 55SX IS ABLE to take two 4MB SIMMS on the motherboard to achieve the maximum of 8MB without an expansion memory board. ============================================================================ D4. What options are there for upgrading the CPU of a PS/2? >Some specs on my machine should be in order. I have an IBM PS/2 50Z (10 MHz) >with 10 Mb RAM and a 60 Mb hard drive, running PC/DOS 4.01 (but I'm planning >to upgrade to 5.0 very soon). > >Up until today, I thought AOX was the only company that provides 486 >upgrades for 286 PS/2s. I found out today that Evergreen Technologies >also have a similar upgrade option called the Evergreen 486 SuperChip, which >by the way sells for $399 ... much cheaper than the MicroMaster (I think it >was in the 4 digit range the last time I've checked). There's gotta be some >major differences then ... anybody knows? > >Unlike the AOX 486 MicroMaster card (which takes up an expansion slot), the >Evergreen chip would replace my 286 chip sitting in the PLCC socket of my >computer. It claims : > > In less than 10 minutes, your 16-bit processor is converted to a 32-bit > processor which can implement the 386's virtual 8086 mode an much > more! Well, my understand is this: The Evergreen 486 CPU uses a Cyrix Cx486SLC. I _think_ it runs at 25MHz. The CPU itself is essentially a 386SX with the handful of added 486 intructions and 1K cache that's not nearly as sophisticated as the cache in the Intel 486, or IBM 386SLC/486SLC2. The chip has no floating point math capabilities by itself (like the Intel 486SX or IBM SLCs.) It's pretty simple, pull out your 80286, and plop in a small board with the Cx486SLC in its place. I'd say the minuses are: (1) Strange math coprocessor options If you buy the model without the math coprocessor, it appears to me that there's no room to add one later. I think you have the spend the money for the math coprocessor model up front. My guess would be that the math coprocessor is a Cx83S87, which is not as fast as the math coprocessor built-in to the Intel 486DX or 487SX. (2) Performance Remember, all you system memory will still be accessed at the same speed. So will the ROM BIOS. As a plus, it's fairly cheap! Based on what I've read, however, I'd feel a lot more comfortable buying the Aox StaX/MC (same concept using an Intel 386SX, with a sophisticated four-way associative cache and much better math coprocessor options) or the Kingston SX/NOW (ditto, except it has a larger cache but it's not as sophisticated... my impression is that it's similar performance to the Aox StaX.) You'd lose the 486 instructions, but I really don't think that's such a big deal with the applications on the market today. >The impression I'm getting so far is that I __CANNOT__ upgrade my 50Z >to a __TRUE__ 386 or a __TRUE__ 486. Is that correct? I'm not >even sure now whether AOX's 486 MicroMaster card is a __TRUE__ 486 >processor, even though I think it's logically possible, as was explained >in their literature. Aox makes three models of the Aox MicroMASTER 486: 25MHz Intel 486SX, 25MHz Intel 486DX, and 33MHz Intel 486DX. I'm not entirely sure of the SX adapter, but the DX models have a 128K cache for RAM and ROM BIOS, and can have up to 16M of RAM on the adapter that is accessed far more quickly than RAM on other expansion adapters and on the motherboard. It's really pretty neat; it's a bus-mastering Micro Channel adapter that takes over CPU tasks of the system. Here are the pluses: (1) Performance The RAM on the adapter is accessed 32 bits at a time. The math coprocessor is built-in to the CPU. (2) Expandability Start with zero RAM on the adapter... go to 16M. It has two SIMM sockets that can take 1M, 2M, 4M or 8M PS/2-type SIMMs. As a side note, I see no reason why the CPU could not be upgraded with an Intel 486DX2-50MHz (for the 25MHz model) or the Intel 486DX2-66MHz (for the 33MHz model.) You'd have to check with Aox to see if this can be done. (3) Backward compatibility You can "turn off" the 486 at boot time and use the native CPU. The RAM on the MicroMASTER is still acessable, although it's not a great memory expansion adapter... The minus is cost. Both in dollars and an expansion slot. (Although the slot isn't so bad when you consider you can load it with RAM.) It's a very nice option, but I couldn't call it cheap. >Are my only upgrade options limited to a 386SX and >a 486SX? Plus, how well would they fare against machines that were >originally a 386SX, 386, 486SX, or 486? Outta curiousity, what is >preventing a common user from purchasing a 386SX, 386, 486SX, or 486 chip >and performing the upgrade by himself/herself? Seems like something >an electrical engineer with microprocessor lab experience can do quite >easily in my opinion. First, don't confuse the 386SX with the 486SX. The 386SX is internally a 32-bit CPU, but is externally a 16-bit CPU with a 16M limit on physical memory. The 486SX in internally a 32-bit CPU with a sophisticated 8K internal cache, and is also externally a 32-bit CPU with a 4G limit on physical memory. The difference between the 486DX and 486SX is that the DX includes a math coprocessor internally. (The 487SX is actually a full CPU plus math coprocessor like the 486DX, so it offers similar performance to a 486DX.) Personally, I don't think a CPU upgrade from a 286 to a 386SX (or similar CPU) upgrade is quite as simple as you describe if any kind of good performance is to be expected. Keep in mind you want the 386SX to run faster than the 286 did, and you'd want an intelligent cache as well. But, I'm not an EE with microprocessor lab experience! I have just called AOX and here are their current list prices :(~9/92) 486SX/25 ... $1600 486DX/25 ... $3319 486DX/33 ... $3397 ============================================================================ D5. Who makes upgrades for a PS/2 computer (company phone #'s) Reply phone- 800-955-5295 AOX Customer Support 800-232-1269 BDS (sells AOXs) 800-950-5657 John Gavern x636 Evergreen Technologies 800-733-0934 IBM Customer Support 800-772-2227 Kingston Technologies 800-835-6575 Xtend 800-232-9836 Phil ============================================================================ D6. What is the Reply motherboard upgrade for the Model 50? PC Week (Jan 25) has a review of the Reply motherboard upgrade for IBM PS/2 50Z. ($895, Reply Corp, San Jose CA 800-955-5295) This is a replacement MCA motherboard that includes SVGA (1 (1 mB) video, IBM 486SLC2 processor IDE disk controller. In a nutshell they liked it. This may be the answer to junking your model 50Z. BTW I read somewhere that IBM was making these MB for reply! Someone else comments: >I think that Reply makes the motherboards for IBM, not the other way. I read some time ago that Reply was bringing out replacements for 386s but have no further information on these. ============================================================================ D7. Should I upgrade my processor or add memory? >I have a 55sx that I am relatively dissatisfied with and would >like to know the best upgrade path. Should I add 4 megs of RAM >(making a total of 8) or upgrade the video card to something with >a full meg of RAM on board. What is the best video upgrade for this >machine? Or for that matter what is the best overall upgrade to >speed the damn thing up running Windows? This should probably be in the FAQ, as it seems to come up periodically. My feeling is that any machine running Windows with 4MB RAM would run better with 8MB, because it will then have to do less swapping to and from disk. This is all the more true of early PS/2s, such as the 55sx and the 70, which had rather slow disk performance. Once the memory has been upgraded, the options are less clear. Is it best to buy an accelerated graphics card, such as XGA-2, and to run it in VGA mode, just for the accelerated VGA that it offers? Would any gain in performance be lost again if the XGA card were driven at a higher resolution (800 x 600, or 1024 x 768)? Or is it better, assuming that VGA resolution is acceptable, to go for a chip upgrade from Cyrix, or a more comprehensive upgrade from Reply or IBM? I'd guess that anyone who went that route would not want to stick with VGA afterwards, and would end up getting a faster video card. ============================================================================ Section E: Peripherals E1. What 5.25" drives can be added to my machine A) I can tell you how things are done with a Cristie drive that I have (in a model 60 with 7 slots). The drive connects to the B-floppy connector. The cable then goes inside the computer, through a slot in the back and finally to the drive. It doesn't actually use a slot, but looks neater than having a connector come from the B drive (which is possible if you don't want to waste a slot). The drive has been working without problems for few years and I can recommend it. But I haven't seen any US-based magazines mention the Cristie (made in U.K.) B) A recent observation about the Radio Shack/Tandy's 5.25" external diskette drive will give you 360 and 1.2MB formats via the parallel port, and allows you to plug your printer in too -- so you lose neither a drive bay, an expansion slot, or much money. The drive seemed temperamental on my model 70, until I realized that so long as I printed something -- even a blank page -- to the printer before trying to access the drive, everything would work smoothly. For those who, like me, just want to be able to read the occasional 5.25" diskette, this drive is an ideal solution which lets you keep your tape backup and expansion cards in place too. C) I have the Sysgen unit. And I'm happy with it. Installed it about 2.5 years ago. Its not a very awkward installation. Just pop off the cover. Unplug the floppy connector. Snap a small board in on supplied post, and re-install the floppy connector and route the other out the box to the external unit. About $300 U.S. at the time. It works as drive B in 1.2 meg mode. The IBM's I saw mapped above the last hard drive, so that floppy came in as D or E. Works fine with SCO Xenix too. D) For IBM floppy drive units, see the item on sources of IBM PS/2 equipment. ============================================================================ E2. What kind of MCA video accelerators/cards are available? Answer: 1) What is available (and currently shipping)? There's XGA-2 from IBM. 2) Are the Windows drivers stable? Rock solid. 3) Are OS/2 2.0 drivers available? Planned? Yes. The XGA driver is in 2.0, but if you want the nice features of XGA-2 you'll want the SP or 2.1. The nice features include: up to 1024x768x256 @ 75Hz non-interlaced, 1360x1024x16, 800x600x64k NI (k=1024 to us hardware types), etc. The modes are determined by what your monitor says it can handle, or you if your monitor lies (and most multisyncs do) you can customize your resolution to your monitor merely by changing your DMQS file to something other than the default. A set of DMQS files is included in the XGA-2 options diskette, or you can roll your own (format is in the tech ref for the hackers out there--I've seen people hack up wierd ones like 1024x1024 and even 1280x1024x16@60Hz NI, but that's well beyond the rated 90MHz dot clock and not supported). All these "nice features" are also available for the Windows drivers. 4) What chipset is used (S3, ATI, WD, Tseng, etc.). IBM, of course. 5) Any Winmark results? 9.9 on the new ones, just about the same as on the old ones. We're one of the few who don't cheat :-) More seriously, there are some comparisons out there that show that WinMarks really aren't very good at measuring coprocessed cards. Your best bet is to try it. From my personal experience, there's nothing out there that's even close to XGA-2 under OS/2, but that's my personal opinion. Besides, I really like seamless windows. High-end MCA video cards (resolution up to 1600 x 1200) are also available from Matrox (1-800-361-1408). ============================================================================ E3. What is the special SCSI connector by IBM? I have just bought a third-party SCSI cable for my PS/2, and it works. It allows you to connect the 60-pin PS/2 SCSI adaptor external connection to any device with a standard 50-pin Centronics connector. So, there are three options for getting this type of connector. By the way, the PS/2 SCSI connector is the same as the one on the RS6000. Of course, the alternative to all this is to use an internal SCSI device, if possible. The IBM *internal* SCSI connections are the same as those found in internal SCSI devices (the 50-pin rectangular connector). Note that on the most recent PS/2s, IBM now uses a more standard SCSI connection, that is like a mini-Centronics (i.e., no need for the 32G4143 mentioned below). FIRST OPTION: Buy the IBM cable from your IBM dealer. The part number is 32g4143. It includes a terminator. It will cost about $50 in the US. SECOND OPTION: Buy a third-party cable. I bought mine from Storage Solutions. Their number is (203)325-0035. Mine cost $75 for a 5' cable (NB: this was at a time when IBM was charging about $200 for their cable). Storage Solutions call the IBM connector a "60-pin compressed" connector (though they are not really pins - it's really a kind of edge connector). They also know what you're talking about if you just call it an RS6000 SCSI cable. Inmac (1-800-323-6905) also sells them (see their UnixSelect catalog). They call it a Mini-Centronics (60) connector. They charge a bit more than Storage Solutions. There are probably other suppliers.The key piece of information is that it is the same connector as on RS6000 machines. The IBM connector is *not* a Mini-SCSI connector. Not all suppliers know this, and they will try to sell you Mini-SCSI (which has 50 pins and is smaller than the IBM connector). THIRD SOLUTION: Make your own. The SCSI connector is available from AMP (1-800-522-6752 or 1-800-526-5142 or (717)564-0100). The AMP part number is 557025-6 (not to be confused with the 557025-5, which is the same connector, but without thumbscrews to hold it in the SCSI port). AMP also calls it a CHAMP .050 Series III Plug Cable Connector. I was unable to find any AMP dealers who could supply this. I had to get it straight from AMP. And it would have been so complicated for them to supply one as a normal order that they sent me one as a free sample.In the end I didn't use it though. It turned out to be almost impossible to solder. It is designed to have each of the tiny SCSI wires forced into a slot that automatically strips the cable. You'd need a special tool to do that. By the way, I bought a cheap SCSI cable and cut one end off, so that I wouldn't have to solder the other end as well. In case anyone is brave enough to try this, here is the pinout. The source is the IBM PS/2 Help Line (1-800-772-2227). But I did not get as far as testing this information, so it would be best to double-check before making the cable: Pin Signal 1 Ground 2 Data 0 3 Ground 4 Data1 5 Ground 6 Data 2 7 Ground 8 Data 3 9 Ground 10 Data 4 11 Ground 12 Data 5 13 Ground 14 Data 6 15 Ground 16 Data 7 17 Ground 18 Data P 19 Ground 20 Ground 21 Ground 22 Ground 23 Ground 24 Ground 25 Not Connected 26 Terminator Power 27 Ground 28 Ground 29 Ground 30 Ground 31 Ground 32 -Attention 33 Ground 34 Ground 35 Ground 36 -Busy 37 Ground 38 -Acknowledge 39 Ground 40 -Reset 41 Ground 42 -Message 43 Ground 44 -Select 45 Ground 46 -Control/Data 47 Ground 48 -Request 49 Ground 50 -Input/Output 51 Reserved 52 Reserved 53 Reserved 54 Reserved 55 Reserved 56 Reserved 57 Reserved 58 Reserved 59 Reserved 60 Reserved This is the same as the pinout for the 50-pin internal SCSI connector, with the addition of the 10 reserved pins. ============================================================================