IBM's codes are very well thought out, so I imagine it means something. Such as my PS1/Valuepoint, is model 433DX. This may not make sense to someone who doesn't know anything about computers, but it breaks down as:
4 = 486 CPU
33 = MHz of CPU
DX = 486 DX CPU, or 486 with Math-co installed.
Actually dude, that's not the model-type-code you are talking about, the model-type-code is what I'm talking about. You're talkingabout the model name. I had one of those computer before, if you look at the lower corner of the front, or do so after removing the cover there should be a little plastic tag that says M/T: xxxx-xxx and another that says S/N - xxxxxxxx that;'s what I'm talking about. Some of the PS/2 model names was derived from the M/T code.
Take for instance you have an IBM PS/2 Model 30 286 for instance, in the original run of IBM PS/2's, the type and code for a PS/2 Machines was 85XX-XXX, so that would make that machine 8530-XXX. The last 3 XXX are kind of like car trim levels: GL/GT/LX/XL/XLT/Sport etc... Basically it indicated what the original options package that computer had. So say if it were an 8530-E21, it'd be an option E21, IBM PS/2 Model 30 286 with a 20 MB Hard Drive rather than a 60 or a 30.
The Model Type Code is basically how one can track an IBM Product to what it originally was. The three originals were 5150-XXX 5160-XXX or 5170-XXX, then there was a first like of IBM PS/2 boxes that were 85XX-XXX, then the early 90's PS/2 Boxes that started with 95XX-XXX through 97XX-XXX, the PS/2 Valuepoints, Thinkpads, Thinkcentres, PC-330/350/370/etc.. all have MTC's as well. It's kind of impressive that IBM Has kept such a reliable tracking method for so long as to finding out what a machine originally was.
So far I've Had My Hands on the Following IBM computers. Mind how hte model name that comes after the MTC can, and usually does, follow the Model number from the MTC (The first 4 digit number).
5160-XXX - IBM PC XT 5160, Friend's computer, was an IBM PC XT 5160 with the usual specs, except it had a 30 Megabyte half height hard drive, a 720K half height floppy, and one full height 360K Floppy drive, and of course, a Monochrome display adaper with a 5151 Monitor. Quite a nice find that was. Never got the code for it.
8530-E21 - PS/2 Model 30 286 with a 20 MB fixed disk installed, 1MB Of RAM, and an IBM Token Ring card as added for use on a college network when it was in commission. This one survived a school fire and was used in subsequecent years after before being given to a professor, who passed it on to me.
8550-021 PS/2 Model 50Z, a 10 MHz 286 machine I sold on E-bay after it was given to me, I had a second one that was dead that I used to repair my model 70.
8570-A61 PS/2 Model 70, 20 MHz 386 DX, 60MB HDD. Was found under a tree in the wood burned and covered in debris, amazingly had little rust, and still worked despite having a few creepy crawlies in the power supply.
0137 (I think) - This was a rebadged IBM PS/2 Valuepoint 433DX/D with a "GTSI Desktop" Badge on the front. where the IBM logo would be. It was a 33 MHZ 486 DX with 8MB Of RAM on 2 72 pin 4MB SIMMS, and came with Windows 3.1 and PC-DOS installed on it, and had one 350 MB IBM IDE Hard Drive in it.
6571-W5K - 100 MHz 486, 8MB of RAM, 540MB Hard Disk Drive, Sure Path BIOS, Model "M" Keyboard, 2nd version of the IBM PS/2 Mouse, and an IBM G40 monitor. Originally shipped with Windows For Workgroups 3.11 & PC-DOS or OS/2 Warp. Seemed to stay in production awhile, mine had some parts in it marked 1997!!! Production started in 1994.
9556-28X - IBM, 75 MHz 486SLC3, SCSI built in, 1.44M Floppy, 12 MB of RAM, 216 MB SCSI Hard Disk. The new one, these came with OS/2 2.1, OS/2 2.0, PC-DOS, or Windows 3.1 installed. They started being made in 1992, mine's a 93' model, and I think they dropped the 9556 sometime around 1995, perfectly fitting as the 9556 does not have a cd-rom.
9545-FBL - IBM THinkpad 755CD, 75 MHz Pentium processor, 1.2GB HDD, CD-ROM, and TFT LCD, one of the first thinkpads with a CD-ROM Drive, I presently own this one, and use it quite a bit. These came with options of Windows For Workgroups 3.11 w/ PC-DOS, OS/2 2.1, and later Windows 95.
2511-451 - IBM Thinkpad I-Series 1400, 300 MHz Pentium Mobile Processor, 14" LCD, and NiMH battery. These are surprisingly still supported by IBM. Came pre-loaded with Windows 98 when it was new.
8191-LS1 - IBM Thinkcentre 8191 - Pentium 4 2.6G processor, 256MB of RAM, 40GB HDD, 48X CD-ROM, WIndows 2000 Professional. Most recent machines from IBM/Lenovo I've worked on, and even now they are still using the MTC to track the original specs. I had to swap hard disks in about 40 of them this past week.