68kMLA Classic Interface
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| LC 475 Project - Upgrades - Mods | |
| Posted by: Kamshaft on 2024-06-26 08:12:56 I have a SCSI bus question. Does the LC475 have two separate SCSI buses? Internal (ID 0 to 7) and external (rear ID 0 to 7) for 16 devices total... OR are is it all shared, internal and external, for 8 devices total? I tried Googling the info, came up empty handed. | |
Posted by: bobcat on 2024-06-26 08:38:10I've emailed the MicroMac folks, maybe i'll get an answer and/or a quote? LOLI think they've been out of business for a long time. I have no idea how their web site stays up. | |
Posted by: bobcat on 2024-06-26 08:42:22I have a SCSI bus question. Does the LC475 have two separate SCSI buses? Internal (ID 0 to 7) and external (rear ID 0 to 7) for 16 devices total... OR are is it all shared, internal and external, for 8 devices total? I tried Googling the info, came up empty handed.Just the single bus | |
Posted by: joshc on 2024-06-26 08:45:57I've emailed the MicroMac folks, maybe i'll get an answer and/or a quote? LOLYou won't get an answer - that site, despite being up, doesn't represent a business that is operating anymore. | |
| Posted by: Kamshaft on 2024-06-26 13:26:50 Someone is getting those emails - Email didn't bounce back. 😆 | |
Posted by: joshc on 2024-06-26 13:50:58Someone is getting those emails - Email didn't bounce back. 😆Yeah, there's a person there. People have called them before and been able to talk to them. They don't have any stock left. | |
Posted by: Powerbase on 2024-06-27 05:27:07Yeah, there's a person there. People have called them before and been able to talk to them. They don't have any stock left. Someone leaves it up to cause suffering and misery. We wail as we look at all the stuff somebody should have bought and stockpiled. We didn't know then that all that stuff was going to be unobtanium later in life. Woe, woe to use. Hear our lamentations. | |
| Posted by: pizzigri on 2024-06-27 14:21:11 especially at those prices. Argh | |
Posted by: nathall on 2024-06-27 20:07:27Yeah, there's a person there. People have called them before and been able to talk to them. They don't have any stock left.One has to wonder why they’re still there answering the phones, in that case…. | |
| Posted by: Kamshaft on 2024-06-28 15:35:00 So, today I ordered the full 68040 @ 33Mhz from the ebay.ca link I posted above. They were asking $70 USD for one, and I offered $60, they accepted. Maybe I should of offered lower. 😛 I'll be doing the resistor swap mod / overclock. Plus I ordered a 45mm x 45mm x 10 mm heat sink, along with double sided thermal tape. Fingers crossed! | |
| Posted by: Andy on 2024-06-28 16:53:53 I've bought a 68040 from Eric Woo's Rare Chips in the past and it worked great. You should be good. | |
Posted by: Kamshaft on 2024-06-28 17:07:34I've bought a 68040 from Eric Woo's Rare Chips in the past and it worked great. You should be good.Sweet! Thanks! | |
Posted by: Brooklyn on 2024-06-28 22:06:16Are you able to tell more details about the SIMM you used?I picked up another 64mb simm from here, it arrived today and works! 
64MB EDO 72pin Low Profile SIMM Ram MEMORY for Amiga Blizzard 1230IV 1230 IV | eBayCompatible with Amiga Blizzard 1230 IV.
www.ebay.com
Picture of my Q605, 52mhz with 68040RC33, 60ns VRAM and spicy o clock. I’m experimenting with the 3D printed fan duct, need to compare cpu temps with/without. | |
| Posted by: Mustermann on 2024-06-29 05:34:10 Chips in the EBay offer are KM44V16104BK-5: 50ns, 4k Refresh 3,6V maximum Supply Voltage. No Voltage regulator visible on front side. The chips in your Macintosh are different but not readable from the photo (Samsung K4E6... I guess) Do you like to tell what chips you got? I am very interested on the experience with the fan duct. I am planning a similar one. | |
Posted by: Kamshaft on 2024-06-29 05:52:51I picked up another 64mb simm from here, it arrived today and works! I just order one, since mine only had 16MB. | |
Posted by: Mustermann on 2024-06-29 07:38:22Picture of my Q605, 52mhz with 68040RC33, 60ns VRAM and spicy o clock. I’m experimenting with the 3D printed fan duct, need to compare cpu temps with/without.Am I right you changed MC88920 into MC88916? | |
| Posted by: Brooklyn on 2024-06-29 09:34:15 e Am I right you changed MC88920 into MC88916?yes, I forgot to include, it is an MC88916W80 | |
Posted by: pizzigri on 2024-06-29 12:19:05yes, I forgot to include, it is an MC88916W80what is the difference? I can’t spot it in the spec sheet, they’re both low skew pll clock drivers…. Is it for the higher clock ? | |
| Posted by: Mustermann on 2024-06-29 14:33:35 MC889xx need to be able to work with double CPU clock. MC88920 is specified up to 50Mhz, MC88916W70 up to 70Mhz and MC88916W80 up to 80Mhz. So for 40Mhz CPU clock an MC88916W80 is the appropriate choice. Others may or may not work. Maybe Brooklyn is able to tell what is needed to change this chip. | |
Posted by: Brooklyn on 2024-06-30 12:12:52MC889xx need to be able to work with double CPU clock.You’ll need a chip and tools/skills to do surface mount soldering. If you don’t change this IC, 33mhz is no problem. If you mod for 40 MHz, I found it actually only runs about 38 MHz with the stock MC88920. Any more likely needs the MC88916W80. | |
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