28 Mar
2006
28 Mar
'06
10:37 p.m.
Michael van Bokhoven wrote:
Hi all!
I have to move a few items on, I've found myself very short on space, so
quite a few classic comp type bits and pieces have to go.
I have a Wang 2200 (just the machine, no peripherals) available, free to a
good home, in Auckland, NZ. It was given to me a while back but I've never
had time to search for the peripherals. Anyone wanting me to ship this will
have to be VERY persuasive. In a couple of days I'll list it on a local
auction site, sale price to go to charity.
This machine was running when decommissioned, and is in good physical
condition. I haven't powered it up, care would be required due to the length
of time since it was last running.
It has multiple cards, looks like all slots have been populated both
internal and external. The IO cards are two multi-function I/O cards
(keyboard, printer/plotter, disk), a typewriter controller (?), a plotter
controller, cassette, video. Internal cards are harder to identify without
spending research time, but it looks about as RAM-populated as it could be.
Pics are here (large image warning - 316k each):
http://host.fenz.net/DSC07196.JPG
http://host.fenz.net/DSC07198.JPG
http://host.fenz.net/DSC07199.JPG
DSC07198.JPG doesn't seem to be there, but DSC07197.JPG does.
Info is here (the site of someone very familiar to
this list):
http://www.thebattles.net/wang/wang.html
heh, heh, it is familiar
The card types are indicated by the numbers on the left side of the 7199
image. The I/O backplane is completely symmetric, but the cards behind
the black cover all have a very specific slot they belong to.
6311+6710+6709 are the CPU. 6311 mostly does control for the I/O bus
that it is adjacent to; 6710 mostly is the ALU (all four bits of it)
plus the eight nibble register file; 6709 is mostly the memory pointer,
the microcode instruction pointer, and the pointer stack.
"ROM" cards: there are two ROM slots but most 2200's fit it all into a
single card as mask ROMs had gotten dense enough pretty early on. These
are the microcode for Wang BASIC. Wang shipped different versions of
BASIC and some options could be added by stuffing in more ROMs (like
MATrix math, and the SORT option). The full blown BASIC occupied 42.5
KB of ROM.
6708 is the timing generator plus it contains a ROM containing the atom
and constant table. in the first generation cpu, the microcode couldn't
read itself. by setting a certain mode bit, reads came from this ROM
instead of from RAM.
RAM: those cards use dynamic RAMs. you'd have to take the cards out and
see how many chips and what type were in it to know how much. the most
ram possible is 32 KB. the cpu has a 16b address, but it is addressing
nibbles, not bytes. the machine is also weird in that in a given cycle
the CPU can either write 4b or read 8b. reads have two addressing
modes: one mode reads nibbles at address PC and (PC ^ 1) to fetch the
two nibbles of a byte; the other mode fetches the nbbles at PC and (PC ^
0x10) to retrieve corresponding nibbles from two locations eight bytes
apart. The latter mode was useful for simultaneously grabbing the
corresponding nibbles of two floating point numbers (in Wang BASIC all
numbers are double precision float, stored in eight bytes in BCD format).
The 2216 display generator is a bit unusual. The stock display
generator for the early machines produced a 64x16 characters. Only 6b
were stored per character, so only upper case letters, numbers, and some
punctuation were available. The 2216 is called a "dual language" card;
it adds another RAM so that there are now 7b per character, and it adds
another character generator ROM, yielding either upper and lower case
ASCII characters, or upper case ascii plus kana characters.