National Multiplex 2SIO (R) Dual Port Serial I/O Board W/Boot ROM For S - 100
Item History & Price
| Reference Number: Avaluer:51464392 | Country/Region of Manufacture: United States |
| Vintage: Yes | Compatible Brand: S-100 |
| Brand: MITS | Type: Serial |
After a fair bit of research I was able to identify this rather rare board. According to an ad on page 35 of Byte magazine issue #16 (December 1976) this 2SIO(R) board is a dual port serial I/O board for Altair or other S-100 systems made by National Multiplex Corporation. From the ad, the "[o]n board ROM (For 8080 and Z80) has terminal and cassette software for turn on and go operation. NO MORE BOOTSTRAPPING. Plug in compatible with Altair and IMSAI. Load...s and dumps memory in Hex from the keyboard, formats tape files, punches tape, functions as a word processor and searches for files and four letter strings within files". This board is intended to be used as an interface for the Computer Aid Digital Data Recorder which, depending on the model, uses DC300 or DC100A tape carthridges, but as the magazine ad indicates it can apparently be used as a boot console with the onboard ROM. I'll include a photocopy of the magazine ad with purchase, but you can probably find scanned copies online to get a higher quality copy. I am unable to test this board so it is being sold as is.
Please check my other listings for more great vintage computing items. I give a discount for purchasing multiple items and of course shipping is combined and discounted.
Free shipping domestically or international buyers pay eBay International Standard Delivery. Local pick-up welcome.
Please check my other listings for more great vintage computing items. I give a discount for purchasing multiple items and of course shipping is combined and discounted.
Free shipping domestically or international buyers pay eBay International Standard Delivery. Local pick-up welcome.
