I had embarked on a project to reverse engineer the boards in my two Wang 2200 machines. I only manged to convert two and a half boards before that effort petered out. Along the way, I ran into a few other people who had done similar things to varying degrees of completion. However, thanks to former Wang engineer Max Blomme, I have some original Wang 2200 schematics to share.
Then in 2016, I was given another set of schematics, this time by Mike Bahia, another former Wang engineer. Although there is a great deal of overlap between the two, I didn't attempt to reconcile them. I simply scanned them and present them as well (below).
Although these schematics were the property of Wang Labs, and what was left of Wang was sold to Getronics in 1999, I'm not sure who holds copyright on them. My intention is not to violate anybody's copyrights, and I hope the rightful holder is OK with me sharing these 25 year old documents for a machine that no longer has any commercial value. The purpose of publishing them is:
- for historical interest
- to aid those attempting to repair a broken 2200
- to help understand the internal operation in order to write an accurate emulation
If the rightful copyright owner wishes me to desist, I will do so immediately. If they instead desire that I include some legal disclaimer, I'd be more than happy to. Since that hasn't happened yet, I hereby state for the record:
I don't own copyright on these schematics, and I do not give right to anybody to use these schematics. If someone somehow has any commercial interest in using this information, I strongly encourage them to seek out the rightful owners of the copyright. In the mean time, I will attempt to do so myself.
All cards in the system have three 30-pin connectors, 15 fingers on each side of the board. Although the I/O cards were on a bus structure, the other cards comprising the system plugged into a backplane that had unique I/O assignment, and the backplane randomly routed the signals to make the appropriate connections. All boards are two layer PCBs. Although the I/O cards have the three edge connectors, the middle one does not connect to the backplane.
The schematics are 11"x17" and were scanned at 600 dpi, 1 bpp. While viewing them at at full resolution on a monitor isn't very practical, the extra resolution is required when printing out the documents. Adobe's PDF viewer also does a nice job of scaling to grey, which makes them much more readable on a monitor.
Here then are all the schematics, broken into separate bundles for easier download. The original set of schematics, from Max Blomme, are available only as 600 dpi 1bpp images.
- Wang 2200 CPU schematics (42 MB; 176 pages)
- Wang peripheral schematics (23 MB; 108 pages)
The second set of schematics, from Mike Bahia, were scanned at 600 dpi, 8b grayscale. They are presented in both 600 dpi 1bpp image form, and as 300 dpi 8b grayscale form. If you find that you need even better quality contact me and I'll send you the uncompressed image scans for whichever pages you need.
- Wang 2200 system schematics, 5/77 (1bpp; 600dpi; 20 MB; 91 pages)
- Wang 2200 system schematics, 5/77 (8bpp; 300dpi; 100 MB; 91 pages)
- Wang Calculator&2200 Peripheral schematics, 5/77 (1bpp; 600dpi; 36 MB; 221 pages)
- Wang Calculator&2200 Peripheral schematics, 5/77 (8bpp; 300dpi; 198 MB; 221 pages)
- Wang Calculator&2200 Peripheral schematics, 1/79 (1bpp; 600dpi; 29 MB; 180 pages)
- Wang Calculator&2200 Peripheral schematics, 1/79 (8bpp; 300dpi; 159 MB; 180 pages)
- Schematic Release No. 31, 6/81 (1bpp; 600dpi; 21 MB; 122 pages)
- Schematic Release No. 31, 6/81 (8bpp; 300dpi; 115 MB; 122 pages)
- Diablo Series 40 Disk Drive Maintenance Manual (1bpp; 600dpi; 27 MB; 134 pages)
- Diablo Series 40 Disk Drive Models 43 and 44 Parts Catalog
- Diablo Model 44B Disk Drive Parts Catalog
The peripherals doc contains peripherals for a number of Wang calculators as well as the 2200. All of them came in one document, so all are offered up as one pdf.
Below are a few of the more interesting pages, broken out as separate documents for examination without having to download the whole bunch.
2200 A/B/C/S/T System Cards (link)
| Board | Function | Schematic | Size | Block Diagram | Notes |
|---|---|---|---|---|---|
| 6522 6560 |
Motherboard | 6522.pdf 6560-rev8.pdf |
642 KB 457 KB |
6522: System motherboard for later A/B series CPUs. 6562: System motherboard for S/T series CPUs. |
|
| 6309 | CPU Registers | 6309.pdf | 365 KB | simple detailed |
This board holds the register file, the instruction counter, the auxiliary registers, and the return address stack. It was used in the A/B/C series CPUs. |
| 6709 | CPU Registers | not avail. | The 6709 is a later, but very similar, version of the 6309, used in the S & T CPUs. | ||
| 6310 | CPU ALU | 6310.pdf | 477 KB | The 2200 CPU contains a 4 bit ALU consisting of a single 74181 chip. Also interesting is the use use of a diode matrix for instruction decoding, and the binary/bcd correction circuitry. | |
| 6710 | CPU ALU | not avail. | The 6710 is a later, but very similar, version of the 6310. | ||
| 6311 | CPU I/O Interface | 6311.pdf | 478 KB | simple detailed |
This board is the interface to the I/O slots of the computer. Besides the I/O address latch and some buffering, this card also holds the K register, ST1, ST2, ST3, and ST4, and generates the I/O one shot strobes ABS, OBS, CBS and receives IBS. |
| 6317 | Keyboard Interface | 6317.pdf | 48 KB | This schematic isn't an official Wang schematic. Instead, it was created by Lex Cunningham, who traced it out from a Wang 2200A he is restoring. | |
| 7025 | Microcode ROM | 7025.pdf | 435 KB | This board holds all the microcode for Wang BASIC. The microword is 20b wide. There is support for six banks of ROM. | |
| 7125 | Microcode ROM | 7125.pdf | 416 KB | This board is a later version of the 7025 with a small change -- there is support for only five banks of ROM. The board layout is also somewhat different. | |
| 6308 | Timing Generator | 6308-1.pdf 6308-2.pdf |
370 KB 321 KB |
detailed | These are two variations on the same function. This card contains the 10 MHz crystal that all other timing is derived from. It puts out variously timed strobes over the 1.6 usec microinstruction period that the other boards use for sequencing. The -2 version appears to be identical to the-1 version except that the -1 version has pullups on inputs D0-D15. |
| 6708 | Timing Generator | 6708.pdf | 401 KB | This is a later version of the 6308, and is used in S & T series CPUs. It contains all the logic of the 6308 plus a 2KB mask ROM that removes the need for a separate atom ROM card (used by A/B/C CPUs). The global strobe scheme is also slightly different. | |
| 6717 | RAM | 6717.pdf | 459 KB | 16Kx8 DRAM. Two could be plugged in for a maximum of 32KB of RAM. |
2200 VP System Cards (link)
| Board | Function | Schematic | Size |
|---|---|---|---|
| 6787 | 32K X 18 Bit Data Memory | 6787.pdf | 1013 KB |
| 6788 | 8K/12K X 24 Bit Memory | 6788.pdf | 731 KB |
| 6789 | Memory Interface Board | 6789.pdf | 431 KB |
| 6790 | Instruction Counter Board | 6790.pdf | 462 KB |
| 6791 | Stack & Program Counter | 6791.pdf | 492 KB |
| 6792 | ALU | 6792.pdf | 547 KB |
| 6793 | Registers & I/O | 6793.pdf | 505 KB |
| 6797 | Power Supply Regulator | 6797.pdf | 265 KB |
| 6798 | Motherboard | 6798.pdf | 510 KB |
Interface Cards (link)
| Board | Function | Schematic | Size |
|---|---|---|---|
| 7079 | Centronics Printer Interface | 7079.pdf | 286 KB |
| 6541 | Disk Controller | 6541-1.pdf | 235 KB |
| 7011 | 80x24 CRT Controller | 7011.pdf | 522 KB |
| 7042 | Keyboard/Printer/Disk Combo Interface | 7042.pdf | 507 KB |
| 6312A + 6313 | 2216 CRT Controller (64x16) | 6312.pdf | 369 KB |