Recent content by frontein1

Yes LOL, I noticed that too after I posted the above. I didn't know that v1.7 was spun up to fix this exact issue. All the Rominators I have use the SST39S040 chips.

OK but wow, this is awesome!! Thank you for sharing.

@max1zzz I have to ask... Where did you get this schematic? This is better than what I have vis-a-vis Bomarc.

That is a really strong theory. I've started doing image searches to see if I can find an example of a board with a populated J11. Yes :) Not an 8MB mod, but actually a trace fix. I bought this LCIII from @jmacz. He has a really detailed thread showing how he resurrected this machine from a...

I wonder how reliable those JTAG connectors would be? However I know there is now a lot of room in the bay to the left where I replaced the spinner with a BlueSCSI. If JTAG could work, then this could be an area. Another idea, and this might be a bad one, would be to 'poke' some holes in the...

LCIII ROM patched and 3MB ROM disk embedded. Happy MARCHintosh! I know, a bit late.... I would have made it in time, but I got a batch of really bad M27C160s from China. So I scrapped them and had to buy and then wait for a new batch. Two M27C160 EPROMs: 1024K x 16 = 2MB each (4MB total). ROM =...

Oh boy, just getting back to this post finally. It would be really cool if there was room for something like dual swipe sockets to make it easier to pull the chips out. Then programming could easily be done with a programmer tool. Of course another option would be to port something like the...

Been doing a lot of tinkering with my MacPlus machines lately. They both have 4MB of RAM. The long memory test time was bothering my, so I patched ROM offset 0x0E0C to 601E. This unconditional branch really speeds up the cold boot. I'm starting to get to the age where I'll take a few minutes...

The SD Card Formatter is probably worth trying. Like it says on the bluescsi.com site, use the overwrite format option to really go low level. https://www.sdcard.org/downloads/formatter/

Looks like I've identified my MARCHintosh project for this year!

I went with the GQ-4X4 from MCUMall. Also with the appropriate adapter and UV eraser. I'll report back on how that bundle works. Interestingly, I took a closer look at the board, and I noticed that the ROM sockets are actually 42-pin each even though the ICs being used are 40-pin. I pulled up...

Thank you @finkmac and @Boctor! Have the ICs and programmer in the mail. Looking forward to having some fun with the LCIII that I originally purchased from @jmacz.

Curious if anyone has tried replacing the stock LCIII ROM ICs with EPROMs? I'm thinking something along the lines of the 27C400, but I am trying to do a pin-by-pin comparison right now. Has anyone done any research on this before? And if so willing to share?

I was thinking that too. I have a 128KB that was old school kit upgraded to the Plus. That has the A revision in it. I just built a CatMac MacPlus and that has a C revision. And for good mid life crisis measure, I just found and ordered a D revision. For my existing A and C revisions, I did...

I've been able to see that there were at least four revisions of the MacPlus board (820-0174 A-D). What I am unable to find is any definitive information on what (if anything) changed between these revisions. Anyone able to shed any light on this?