image of READY prompt

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:

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.

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.

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
Motherboard 6522.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
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
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
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
6316 2217 Cassette Controller not avail.  
6367 2222 Keyboard Controller not avail.