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Hi everyone, My friend Garrett Fellers and I design, manufacture, and sell vintage hardware through his Garrett's Workshop brand. One of our products that's been out for a while is our GW4201-series "RAM2GS" RAM expansion card for Apple IIgs. (eBay...

Sorry for my absence--please check your PMs. Yes, it should have been programmed when sent to you, but a mixup could have happened. I am not sure if the programmer can program my ROM SIMM, but it can certainly read it out (if indeed it originally supported that feature). The ROM is here, named...

The memory manager only moves memory when you make a call to allocate a pointer or handle, or when you call a (toolbox) routine which does the same. Memory never gets moved at interrupt time, so it’s not like you can be going through the code and all of a sudden the memory you were using has...

Yes, but I think it's better to have 6.0.8 on the 2MB and 7/7.1 on the 8MB. The RAM disk (which of course you don't have to use) requires 7.5MB of RAM on the 8MB SIMM but only 1.5MB on the 2MB, so it's sort of fitting that the 6.0.8 version has a smaller RAM requirement to use the RAM disk. Ooh...

Yes, I believe so, but you have to break it up into its own function like so: asm void foo() { ... }

For the record, CodeWarrior 6 works quite well on my unaccelerated SE/30, and I recently used it to develop the control panel for my ROM disk. My impression is that CodeWarrior is basically a THINK C clone but the compiler is a bit more modern. Only issue was that I had to hook up a SCSI CD-ROM...

Wow, that’s interesting about the virtual memory manager. I didn’t realize it did that. But what about the need to keep an application’s RAM contiguous? Surely the VMM can’t split an application partition across multiple 1MB chunks—or can it, and then just suffer the resulting fragmentation, as...

Thanks for the feedback! I'll install 7.1. Now about the CD extension, I generally use FWB CD Toolkit because I can set a massive driver cache size with it, but I think it would be more appropriate to include Apple's CD extension. Now, version 5.3.1 seems to be the right version to use, but this...

Oh, I forgot to ask in my earlier post: what software should I include on the 8MB SIMM? Currently I have: System 7.0.1 TeachText Lido and PMount Disk First Aid ResEdit HexEdit What else should I include? Is System 7.0 the right choice or should I include 7.1? And can anyone...

2MB SIMMs are being tested now, and I am so far hearing only good things! 8MB SIMM boards just arrived: I'm waiting on a single part to come and then I can assemble these. Regarding the thickness, I was able to get a few quotes for 1.3mm boards. The best price was around $4 each, which is...

As we all know, 68k Mac compacts have a hardware RAM limit of 4MB. However, there exist accelerators (e.g. Radius Accelerator 16) which extend the memory capacity to 16MB using onboard SIMMs. Presumably 8MB of this RAM is accessible in 24-bit mode. So my question is, what’s the typical memory...

Huh, I just checked on my SE/30 and you're right, the IIsi ROM does support HD20 booting. That's strange because it says in the Mac IIsi Developer Note that it's only supported with an INIT. Well that's good! Edit: "IIsi Developer Note," not "IIci"

Unfortunately I don’t yet have a Mac II ROMBUS design but I am thinking about it. Right now there’s just the Plus/512 version finished. The peak read speed on the Plus will be 2 bytes/12 cycles using a MOVE.W (A0), (A1)+ instruction. That’s 1.3 MB/sec. So it should be much faster than SCSI on...

Well, I think it started about a year ago, when I noticed that BMoW’s ROMinator was discontinued. I designed a similar board, which I called ROMBUS, that plugged into the Mac’s ROM sockets but was equipped with 64 MB of cheap serial flash memory as well as the parallel flash toolbox ROM. This...

I've fixed some more System 7.5 issues. After a long while debugging crashes and other issues on 7.5, I have finally figured out the root cause. My ROM disk driver replaces the .netBOOT driver, same BMoW's and BBraun's drivers do. However, System 7.5 has special handling of the .netBOOT driver...

The 7.5 bug is fixed! I I have been testing the driver in my IIsi for some time with no issues. And wow--System 6 boots up from the ROM disk extremely quickly. I measured something like 7 seconds from the "bong" sound to the desktop on my IIsi. I will be installing the ROM SIMM in my SE/30 and...

Hmm yes, I guess they are very rarely gold-plated. Either way, I don't think the layer of flux would be good for connectivity. We will look into what can be done about this, but as far as we can tell, good contact is being made. No, this is a separate issue, and yeah, the patch will be required...

I've updated the spec to fix a few mistakes, and I've also added some sample code to operate the ROMBUS from the Mac, which I'll reproduce below:   #define SIGR_WR ((short*)0x41FFE0) #define CSR_WR ((short*)0x41FFD8) #define CSR_RD ((short*)0x41FFD0) #define RXR_RD ((short*)0x41FFD2)...

There's some tolerance so I think it'll work okay. One danger with tinning the contacts is that gold doesn't corrode and makes better electrical contact than solder and other metals. For example, it takes some force to get an accurate resistance measurement using nickel-plated multimeter probes...

There's one bug I'm aware of which I have yet to squash in my driver: System 6-7.1 work but System 7.5 crashes on boot. Once I fix this, I can send out some test units. In the meantime, I have just sent the 8MB SIMM off to production. 1.2mm thickness. Technically SIMMs are supposed to be 1.27mm...