Custom ISA-ish SSD interface board for vintage laptop - Page 1
Forum section: electronics / projects

author: johnwa
author_rank: Frequent Contributor
timestamp: February 17, 2024, 01:15:32 am
content: Hi all, here is my latest project. It is a custom Micro SD adapter for a vintage MS-DOS floppy-only laptop. The machine didn't have any suitable expansion ports, so I had to reverse engineer a proprietary port that was intended for an internal modem. This turned out to be fairly similar to an ISA slot, though with a custom pinout. Full story athttp://loopgain.net/multispeedhdd/, or jump to the card development athttp://loopgain.net/multispeedhdd/part3.html

author: Stray Electron
author_rank: Super Contributor
timestamp: February 17, 2024, 01:19:24 am
content: I'm envious. I bought one of those new in 1985-ish and it was a great computer. I gave it away years ago but now I wish that I had kept it.

author: johnwa
author_rank: Frequent Contributor
timestamp: February 17, 2024, 01:23:52 am
content: Yes, it's not a bad machine, MS-DOS compatibility was quite a useful feature which not all portables had back then. What software did you use with your unit Stray Electron?

author: Stray Electron
author_rank: Super Contributor
timestamp: February 17, 2024, 02:58:11 am
content: I used alotof Lotus 123 and Dbase III for business purposes. I can't even begin to tell you how many reports, analysis and other documents that I created using those two programs. As crazy as it might seem I also wrote a lot of utilities to convert files from an IBM mainframe for use on a Micro-Vax. Our company had a huge amount of data that had been generated over the course of about 2 1/2 years on the IBM mainframe (I don't know what model) and we had to deliver it to a company in Canada. But they were using a MicroVax and every time we tried to upload the data it would crash the upload program. I finally figured out that there were all sorts of non-ASCII characters in our data that the MV treated as control character such as an End of File flag. I actually ran WordStar in a non-text (binary) format to search and replace all of the characters that were causing problems and replace them with harmless characters, usually Z so that if we needed to we could locate them in the data set after it was uploaded to the MV and fix them as necessary. I spent nearly three weeks just on that job alone! At the time, I had the only personal computer in that company in Canada and I only had because I had bought it as a personal toy and taken it up there with me but it really saved the day; for both companies.One other quick and dirty program that I wrote was a Mil Standard decision tree process to identify failures and their possible consequences. The data that we had generated in the US was completely scrambled so I wrote a quick and dirty program (with lots of GoTos) and I went through and answered all of the questions and simply created a new data set. I had been one of the first engineers on that program and I had been one of the people that did the same analysis the first time around so I was able to answer the questions pretty quickly. I think that took about one day to write the program and another three days to answer the questions. After I returned to the US I showed what I had done to our data systems representative and they liked it and copied used it for all programs that had similar requirement. That program was written BASIC., I THINK the BASIC that came with the computer but possibly MS BASIC.When I got ready to leave Canada, the security department there about S&*t a Brick when they found that I had computer and that it had a battery backed RAM disk in it! And that I had probably 60 3 1/2" floppy disks with all sorts of programs and files. They had no way to examine the smaller disks and they didn't seem to know enough to know how to examine everything so they seized my computer and disks and sent all of it to Montreal for analysis. I got all of it back three days later.I guess that I can talk about it now. This is what we were building.https://www.army-technology.com/projects/adats/I was the first technical rep from MMC to the startup company Oerlikon Aerospace, now Rheinmetal, in Saint-Jean-sur-Richelieu, Canada that was going to build the CF LLADS system.

author: johnwa
author_rank: Frequent Contributor
timestamp: February 18, 2024, 01:12:13 am
content: Right, sounds like you got a lot of use out of your machine! We never had Lotus on ours, just the spreadsheet component of the "ABLE-1" office suite, but that was enough for me to learn the basics of spreadsheets. On the machine that replaced the Multispeed, there was a clone of Lotus called "ASEASYAS" (as easy as 123 - get it?), though by that time Excel was starting to take over.And I never really used dBase either - by the time I had developed an interest in that sort of thing, technology had moved on. There was some sort of database in ABLE-1 though, I can remember it being used for customer mailing lists, printing address labels on tractor-feed self adhesive label stationery.I can understand the security guys being pretty perplexed by the machine, it was all pretty new technology back then! I'm glad you managed to get it all back in the end.

author: brittman914
author_rank: Newbie
timestamp: December 08, 2024, 06:15:02 pm
content: If by any chance you still have any boards left over, I'd love to buy one of these. I actually bought a new-in-the-box working NEC Multispeed during COVID, and have a parallel port hard drive connected to it. While it does work, I'd love to have something internal to use.I was actually starting to look for a pinout for the modem card in hopes I could adapt the parallel port SD project to a internal card, and stumbled on your site, and this thread.