68kMLA Classic Interface
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| Dynamac EL manual? | |
Posted by: james_w on 2017-03-06 04:12:55For anyone finding this thread in the future, here's a link to the software for the Dynamacs, courtesy of haplan. Link: http://archive.compgeke.com/Drivers/Mac/Clone%20Stuff/Dynamac/😛b: | |
| Posted by: haplain on 2017-03-06 08:56:21 Hoo ray for keeping some history alive | |
| Posted by: apm on 2017-03-12 09:26:45 Having seen this strange beast in person, I was curious how the 640x400 video board works. Disassembling the "640 x 400" INIT from haplain's archive revealed a few tidbits: Hardware The DynaMac is based on a Plus logic board with stock ROMs. It appears that the VRAM for the DynaMac 640x400 display lives at $780000 in memory. That makes sense because it's an unused address space on the Plus. There appears to be a control port at $7A0001, i.e. the low byte of address $7A0000. The Plus has a 16-bit bus but a lot of the peripherals use only 8 bits. Some of them are connected to the low byte of the bus while others are connected to the high byte. I don't know why that is, but anyway, it's the low byte (A0=1) here. Reading and writing bits to this address must query or set the status of the display somehow. INIT Most of the INIT seems concerned with a bunch of stuff relating to the cursor, which I didn't bother to pick through so I don't know exactly why it's there or what it does. But the interesting part starts at address offset $37C in the INIT resource. The approximate plan seems to be: 1. Check if the system ROM is what it expects. If not, exit. 2. Twiddle a series of bits on the control port at $7A0001 (this is the code starting at $398) -- Set and test bit 3. If it reads low, exit. -- Clear and test bit 1. If it reads low, exit. -- Set bit 0, then read bit 2. If it reads high, exit. 3. Draw a grey checkerboard pattern in video memory at $780000. (this is the code starting at $3F6) 4. Copy the video data from the old screen address (i.e. in Plus system RAM) to somewhere within $780000 -- I think with a row / column offset, but I'm not sure. 5. Update the QuickDraw variables to point ScrnBase (i.e. the screen memory address) to $780000 and update the size to 640x400. 6. Call some system trap stuff that I haven't worked out, but probably gets QuickDraw to sort itself out again. I'm guessing that some part in Step 2 (twiddling control bits) must flip a switch to tell the DynaMac video hardware to display from its native VRAM rather than from the Plus video. Then it's just a matter of pointing QuickDraw to the new VRAM buffer and away you go. | |
Posted by: ConventionalMemories on 2023-12-27 19:20:07For anyone finding this thread in the future, here's a link to the software for the Dynamacs, courtesy of haplan. Link: http://archive.compgeke.com/Drivers/Mac/Clone Stuff/Dynamac/This link seems to be down. anyone have a backup they could share? tnx | |
Posted by: Compgeke on 2023-12-28 10:02:01This link seems to be down. anyone have a backup they could share? tnxOnce I get home next week I can bring it back up. That web host is with the lord now, but I've got a full site backup still. I'll merge it into the newer-and-greater project 🙂 . | |
Posted by: ConventionalMemories on 2023-12-28 20:14:04Once I get home next week I can bring it back up. That web host is with the lord now, but I've got a full site backup still. I'll merge it into the newer-and-greater project 🙂 .Great, thanks. If you could share a copy of that dynamac folder. That would be great. Cheers. | |
Posted by: ConventionalMemories on 2024-01-17 17:26:31Once I get home next week I can bring it back up. That web host is with the lord now, but I've got a full site backup still. I'll merge it into the newer-and-greater project 🙂 .Have you've had a chance to look for the files by any chance? I would love to get my Dynamac up and running 🙂 | |
Posted by: Compgeke on 2024-01-19 09:07:25Have you've had a chance to look for the files by any chance? I would love to get my Dynamac up and running 🙂Finally back home! Had myself gone 3 of the last 4 weeks 🙁. Here's a link: index - powered by h5ai v0.30.0 (https://larsjung.de/h5ai/)index - powered by h5ai v0.30.0 (https://larsjung.de/h5ai/)
fsck.technology
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Posted by: ConventionalMemories on 2024-01-19 15:42:53Finally back home! Had myself gone 3 of the last 4 weeks 🙁. Here's a link:Thank you, that will help a lot, 😉 | |
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