I'm trying to add WE32106 Math Accelerator support to my 3B2 emulator. So far so good, but I feel dirty: My code assumes floating point types are stored in IEEE-754 format in memory. The C standard guarantees no such thing.

I mean... so far it works? But there's no guarantee it will work on every platform, or even with every compiler.


@twylo I had never heard of that line of computer until your post. I had come across the AMD bitslice parts long ago when reading through books filled with datasheets from vendors was a (sometimes) fruitful thing to do. Anyway, it looks like an interesting piece of computer history. :)

@twylo Woke up this morning and finished reading wikipedia page and realized I was confused by model names. Your 3B2 was not implemented with bitslice ICs. As far as CPU goes, was there any architectural heritage between the large 3B20 and the WE-32000 used in the 3B2?

@cstanhope I don't know much about the 3B20, but I believe it was based around the same BELLMAC architecture that informed the WE32000 and WE32100 chipset.

@twylo Cool. Thank you. I'm curious, since you're building a 3B2 emulator, did you use one of those machines before?

@cstanhope Believe it or not, no. I became really interested in the platform in 2014, and couldn't get my hands on a real 3B2, so I started writing the emulator to better understand it. One thing led to another, and now I have a small pile of 3B2 hardware and a working emulator.


@twylo That's awesome! I admire your tenacious drive to understand the system. 😀

Sign in to participate in the conversation

social.coop is a cooperatively-run corner of the Fediverse. The instance is democratically governed by its members, who generally share an interest in the co-op model, but topics of discussion range widely.

If you are interested in joining our community, please review our Bylaws and Code of Conduct. If you agree with them, you may apply for membership on our instance via this link

Our instance is supported by sliding scale contributions of $1-10/mo made via Open Collective. You must have an active Open Collective account to apply for membership; you may set one up here