Hello Everyone!

Paralel

Tinkerer
Dec 14, 2022
115
47
28
Glad to be here! I wasn't aware that this place existed until just recently.

I've tinkered in IT since I was a teenager and eventually worked in the field as an adult. I've been involved in vintage computing, specifically Compact Macs, 68k Powerbooks, Tandy/GRID notebooks, & parallel port soundcards for about 15 years now. I was the other 1/2 of the team that created the first homebrew ROM expansion/Math co-processor expansion card for the Mac Classic II. I'm a System 7.1.x evangelist.

I've been a member of 68KMLA, Vintage Computing, etc... over the years. I'm essentially a refugee from 68KMLA.

My current interest is on trying to adapt a TI 486SXLC-040-PJF as a replacement for a Cyrix Cx486SLC-20 in a GRID laptop who's original design was intended for the Intel 80386SX-20.
 

eric

Administrator
Staff member
Sep 2, 2021
822
1,307
93
MN
scsi.blue
I'm a System 7.1.x evangelist.
The best System IMHO

I wasn't aware that this place existed until just recently.
Where did you hear about us? And glad you did!

I was the other 1/2 of the team that created the first homebrew ROM expansion/Math co-processor expansion card for the Mac Classic II
Nice! I have one in my Classic II! (not sure if it's your design or another though)
 

Paralel

Tinkerer
Dec 14, 2022
115
47
28
The best System IMHO


Where did you hear about us? And glad you did!


Nice! I have one in my Classic II! (not sure if it's your design or another though)

Your taste in System software demonstrates you are a man of refinement and good taste.

I found out about this place through a post someone made on 68kMLA. I drop by 68k about once a year or so to see if anything major has happened, and I was surprised to hear about (yet another) major crash. Someone posting about it mentioned this forum and I immediately hopped on over and joined up.

If it's the Classic II expansion card that has the socket for the ROM expansion, it's definitely the one that Alaska and I worked on. As far as I am aware, no one else ever made another card that included the ROM expansion. Mainly because it requires a 4-layer board minimum, which costs more than the 2-layer board needed for just the FPU, and most people weren't terribly interested in the ROM expansion. Personally, I find the ROM expansion to be a substantial advantage. It's possible to put a minimal System 7.1.x installation on the ROM and use it as a ROM Drive just like the original Macintosh Classic.

I eventually plan to make another version of the board that includes a PGA socket since that would allow for the highest speed FPU, 50 MHz. Not that there is a huge difference between the 40 MHz PLCC and the 50 MHz PGA, but it's the same reason we do anything, because it can be done!