Software Results Corp Unibus 68000 board?

--- CLASSICCMP(a)trailing-edge.com wrote: Yup. Cool. Out of perverse curiosity, what's the S/N? I can eventually look it up and tell you who used to own it. I might have even been the guy that pulled the parts from inventory and tested the finished product. Nope... the company got tired of snooping down bad chips. The boards were a couple of grand, customer cost, so MIL-SPEC chips were not a horrible cut into the profit margin and were, at the time, individually tested. It saved enough on labor to be worth the expense. It is an intellegent synchronous serial card with onboard line-printer capability. On a RSTS/E system, you could avoid spooling jobs through the system line printer queue, saving many CPU cycles. We used to hang LA-180's right off of the printer port or sell a printer adapter for Dataproducts interfaced printers. Yes. I was hired there in 1984 and eventually bought the name and rights to the software/hardware/customer list and provided service between 1993 and 1995 to all the customers who bought them in the 1980s (by 1990 sales were effectively non-existant except for upgrades). Coincidentally, SRC was the company that took out the full page back ad on "CPU Wars", now on the web at http://www.e-pix.com/CPUWARS/cpuwars.html I have all the software, firmware, schematics, wire-wrap prototypes, *everything* for them. Unless you want to speak 3780 or HASP to some other device from your Unibus PDP-11 or VAX, that board is useless. The dual 6309 PROMs are only smart enough to feed more complicated programs through a CSR window into the 16K of SRAM. Even simple diagnostics are downloaded at runtime, character by character. In its protocol emulation mode, it uses 16-bit DMA to feed buffers back and forth. Unless I am seriously misinformed, this board was the first single-board DMA device for the Unibus. Software Results pioneered the removal of the NPR jumper to allow such things to work (prior to this, DMA devices were one _backplane_ that broke grant between the input and output Unibus cables). We had to ship dual-height grant cards to accomodate the absence of the board when it was removed for diagnostic or repair purposes. More trivia: this board uses SRAM because of two early DRAM problems. Intel RAM was having higher than expected single bit errors (thought at first to be cosmic rays, but later proven to be stray alpha particles emitted from the minute quantities of radioactive materials in the ceramic packages). Additionally, the first batch of 68K CPU chips (my old boss still has XC68000 S/N 424, yes, there is a serial number engraved on the lid) had microcode glitches that caused longer than advertised bus cycles. For those designers that borrowed/copied/migrated existing Z-80 refresh schemes, the outages were long enough to interfere in some cases, causing catastrophic memory loss. SRC went with 2114s for reliability. ===== Infinet has been sold. The domain is going away in February. Please send all replies to erd(a)iname.com __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com