MarkO Posted June 26, 2021 Share Posted June 26, 2021 On 6/20/2021 at 3:36 PM, AtariLeaf said: Correct I think you need a minimum of 64k for the CocoSDC. Mr Dave if I didn't already have a Coco joystick adapter coming from Neil Blanchard (we're both in Canada) I'd order one of yours. Nice work. The CoCoSDC has the "same requirements" as RS-DOS... 16KB RAM and Extended BASIC... But 16KB won't leave any RAM for Programs, so 32KB is a _minimum_ RAM level for a working system.. MarkO Quote Link to comment Share on other sites More sharing options...
Gunstar Posted September 22, 2021 Share Posted September 22, 2021 (edited) Hello, new Coco 2 owner here, I started another thread about that, I upgraded to 64K the first day I had it. but in several different Coco forums I keep hearing people say "you want a minimum of 64K" or for this or that you need a minimum of 64K. I've been doing my research since purchasing one for repair, and I know it's 4K beginnings and 16k, 32k, 64k upgrades and revisions and new models, and the extended basic rom upgrade, etc., but I have not seen anything anywhere about upgrading Coco 1's and 2's beyond 64K. I'm aware of the Coco 3 stock 128K and traditionally can be upgraded to 512K. Do new home-brew or legacy DIY projects or third-party upgrades exist for the Coco 1 & 2 for 128K or 256K or more with bank-switching? What modern hardware devices complete and for sale, kits or DIY project schematics exist beyond the CocoSDC and making your own program pak boards? I also recently read about the last Coco 2 revisions having a new video chip with true lower case? Can other Coco's be upgraded to this newer chip and if so, is it just swapping or are there additional modifications required? I'm a big fan of hacking, modding and upgrading vintage machines, making them the best they can be or could have been. And now that I've taken the plunge into TRS-80 Coco's I want to make my Coco 2 the best it can be, totally trick it out, as much as possible, short of it being a Coco 3. And I always loved the larger Coco 1 style computer case, and the grey metallic look of it and the early peripherals, but I didn't get one because of the keyboard. now that I know I can use another Coco 2 keyboard or after market, I am definitely getting one and upgrading it to the max too. Of course all of these questions I have are prior to going to the links for Coco support in this thread I just bookmarked and am headed to now. So I may find the answers I'm looking for... Edited September 22, 2021 by Gunstar 1 Quote Link to comment Share on other sites More sharing options...
MrDave Posted September 22, 2021 Share Posted September 22, 2021 There is not much limit what can be done with a covo.. the mooh can give 2 meg i believe coco vga gives vga out + lots of tweaking to fonts etc.. i gave mine wifi and usb.. sloopy sells wifi boards to put in your coco to access drivewire.. here was my coco2 last year.. 1 Quote Link to comment Share on other sites More sharing options...
MrDave Posted September 22, 2021 Share Posted September 22, 2021 I have coco pcb boards with / without leds thst can bank switch larger roms or put original games on them if you need some Quote Link to comment Share on other sites More sharing options...
Gunstar Posted September 23, 2021 Share Posted September 23, 2021 (edited) 21 hours ago, MrDave said: There is not much limit what can be done with a covo.. the mooh can give 2 meg i believe coco vga gives vga out + lots of tweaking to fonts etc.. i gave mine wifi and usb.. sloopy sells wifi boards to put in your coco to access drivewire.. here was my coco2 last year.. That is VERY cool. I'm glad to here there are quite a variety of hardware upgrades and mods to do to the Coco line, just like I've been doing to my Atari 8-bits. I watched on Coco Youtube video with a Coco 1 that had a old-school/legacy DIY board in it for lower-case letters and different fonts, with 3 toggle switches underneath to turn them on and off. I did visit some links in this thread and found the mini-EPI and Mega-Mini-EPI devices, though most are sold out, including the version I would want, the Mega. I'll keep look for original EPI perhperals too. And I found out about a few other upgrades and modern expansion hardware like on the Atari. I'm VERY glad to know about the Coco Livewire, as I have Fujinet for my Atari's and I love it! I'm also glad to here there are extended memory upgrades for the Coco 1 & 2. My Atari 800 has 1MB and my Atari 1200XL has 576K. I ordered the 24-to-28 pin EBOS board from The Zippster Zone, and I have an eprom burner and 2764's on hand for that upgrade. I may get the VGA upgrade (I have RGB/VGA/DVI video board upgrades for my Atari's) But I'll first do a composite/S-video mod before I purchase. I checked out the video mod hacks and RF replacement boards, but I have some unique experience in video upgrades and I believe I can do my own custom S-video circuit with some custom tweaks of my own and come up with a better solution myself. Edited September 23, 2021 by Gunstar Quote Link to comment Share on other sites More sharing options...
Gunstar Posted September 23, 2021 Share Posted September 23, 2021 (edited) 21 hours ago, MrDave said: I have coco pcb boards with / without leds thst can bank switch larger roms or put original games on them if you need some Yes, I do think I will need some. Of course I'll get a CocoSDC soon, but I have CF & SD card drives for my Atari's and it certainly doesn't stop me from using real cartridges, tapes and disks and the real drives still. I'm sure I will feel the same way about the Coco. Are there any sites that have classic and/or new Public domain/open-source hardware project plans and schematic archives for DIYer's like myself as well? Edited September 23, 2021 by Gunstar Quote Link to comment Share on other sites More sharing options...
MrDave Posted September 23, 2021 Share Posted September 23, 2021 On 6/2/2020 at 12:22 AM, Schmitzi said: Looks interesting! Quote Link to comment Share on other sites More sharing options...
JamesD Posted September 24, 2021 Share Posted September 24, 2021 On 9/22/2021 at 6:50 PM, Gunstar said: Yes, I do think I will need some. Of course I'll get a CocoSDC soon, but I have CF & SD card drives for my Atari's and it certainly doesn't stop me from using real cartridges, tapes and disks and the real drives still. I'm sure I will feel the same way about the Coco. Are there any sites that have classic and/or new Public domain/open-source hardware project plans and schematic archives for DIYer's like myself as well? There were many hardware related articles in various color computer magazines, but I'm not aware of any recent plans being publicly posted Quote Link to comment Share on other sites More sharing options...
Gunstar Posted September 24, 2021 Share Posted September 24, 2021 (edited) 12 hours ago, JamesD said: There were many hardware related articles in various color computer magazines, but I'm not aware of any recent plans being publicly posted I'm thinking of more archival stuff from magazines or other home-brew upgrades and mods done and archived on the internet in the last 20 years or so. The reason I ask is because you can find just about any hardware upgrade or mod ever done for the Atari 8-bits on someone's site or repository/archive or even within forums as threads and links. I expected similar in the Coco community. Maybe it's just the larger community surrounding Atari 8-bits which includes more active electronic guru's actively making new upgrades and devices for it. I have found some stuff, but it all appears to be purchasable mods and upgrades, like dual-6809 boards, and 24 to 28-pin OS boards and plenty of upgrade devices/boards that attach to the expansion/cart port that are all for sale (and many sold-out). In the Atari 8-bit community we have the same thing, but the designs and schematics for anything purchasable is generally available for anyone who wants to make their own versions. But I'll just have to start making my own from scratch I guess, like my own composite/S-video mod I am doing now, since the ones I've found instructions or videos for online for the Coco 2 are not good enough for me, except the CocoVGA board upgrade, which I will get eventually, but I still need standard video for all the software that uses artifact color graphic modes, so I'm designing my own. I was hoping to find the schematics for the Mega mini-MPI, but the manual doesn't get that detailed and haven't found any source for a schematic. Edited September 24, 2021 by Gunstar Quote Link to comment Share on other sites More sharing options...
JamesD Posted September 24, 2021 Share Posted September 24, 2021 You can try here: https://colorcomputerarchive.com/repo/Documents/Magazines/ 1 Quote Link to comment Share on other sites More sharing options...
MarkO Posted September 29, 2021 Share Posted September 29, 2021 On 9/21/2021 at 8:24 PM, Gunstar said: Hello, new Coco 2 owner here, I started another thread about that, I upgraded to 64K the first day I had it. but in several different Coco forums I keep hearing people say "you want a minimum of 64K" or for this or that you need a minimum of 64K. I've been doing my research since purchasing one for repair, and I know it's 4K beginnings and 16k, 32k, 64k upgrades and revisions and new models, and the extended basic rom upgrade, etc., but I have not seen anything anywhere about upgrading Coco 1's and 2's beyond 64K. I'm aware of the Coco 3 stock 128K and traditionally can be upgraded to 512K. Do new home-brew or legacy DIY projects or third-party upgrades exist for the Coco 1 & 2 for 128K or 256K or more with bank-switching? What modern hardware devices complete and for sale, kits or DIY project schematics exist beyond the CocoSDC and making your own program pak boards? I also recently read about the last Coco 2 revisions having a new video chip with true lower case? Can other Coco's be upgraded to this newer chip and if so, is it just swapping or are there additional modifications required? I'm a big fan of hacking, modding and upgrading vintage machines, making them the best they can be or could have been. And now that I've taken the plunge into TRS-80 Coco's I want to make my Coco 2 the best it can be, totally trick it out, as much as possible, short of it being a Coco 3. And I always loved the larger Coco 1 style computer case, and the grey metallic look of it and the early peripherals, but I didn't get one because of the keyboard. now that I know I can use another Coco 2 keyboard or after market, I am definitely getting one and upgrading it to the max too. Of course all of these questions I have are prior to going to the links for Coco support in this thread I just bookmarked and am headed to now. So I may find the answers I'm looking for... Gunstar: The CoCo 3 uses an MMU in the GIME to Switch 8KB Banks in and out of Memory... These 8KB Blocks can "basically" be located anywhere in the Memory Map. Traditionally the CoCo 3's would be Expanded to 512KB, but OS9 can use up to 2MB, and there are modern memory boards that are available with 512KB and 2MB and some Brand New ones that are 8MB... The Mooh and the CoCoPSG both have 512KB of RAM, ( and the CoCoPSG has 512KB of Flash ) , also the CoCoPSG is limited to the last 8KB or 16KB in the Last 16KB of the Memory Map, where as the MOOH seems more flexible.. https://subethasoftware.com/2020/04/19/understanding-and-using-the-coco-3-mmu/ http://www.cocopedia.com/wiki/index.php/MMU_RAMROM_Mode http://tormod.me/mooh.html https://thezippsterzone.com/2018/05/08/coco-psg/ The "last version" of the CoCo 2 has a different Video Chip/ROM ( called the T1 ) that has Lower Case.. You can't "retrofit" the older CoCo 2s, or CoCo 1s with this Chip, because the Pin Out is different, and I believe there is a Timing Issue... Ed at the Zippster Zone has replacement Keyboards that can be used in the CoCo 1, and there are 3rd Party Keyboards, made back in the 1980's for the CoCo's.. https://thezippsterzone.com/2018/09/14/coco-mech-mechanical-keyboard/ There are quite a few Hobbyist Projects for the CoCo that are posted on the 'net. I can dig a few of them up for you, but it will take a bit.. MarkO 2 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 1, 2021 Share Posted October 1, 2021 (edited) Thanks @MarkO, I've been doing a ton of research and have discovered for myself some of what you refer too. I have already upgraded to 64K, I purchased and installed Extended Basic rom board for fitting 28-pin chips with rom included., I have a 6309 replacement MPU on the way now as well as the MOOH. I'm waiting until an original multi-Pack Interface comes my way, since the Mega-mini is sold out and the regular mini with two ports isn't enough, besides, I want a real case, the 3D case designs for the repros suck. I also found out about the last VDG chip with lower case and have been scouring the internet for it, without luck, so I may just have to see about another option for external (to VDG) character roms. I plan to eventually get the CocoVGA board, I recently installed something similar for Atari 8-bits called Sophia 2. I am also in the middle of an S-video upgrade, I'm just waiting on a couple of transistors to arrive today. As for the keyboard, the melted one that came with it is fine for now. I may eventually get a Coco 1 and transplant the keyboard into it and then upgrade the Coco 2's. But I've checked and places that sell the upgraded keyboard, like many other items for Coco's, are sold out. Edited October 1, 2021 by Gunstar Quote Link to comment Share on other sites More sharing options...
swissarmytin Posted October 4, 2021 Share Posted October 4, 2021 Guess I'll post in here instead of making a new topic, but I'm a new owner of a CoCo 2, rev 26-3134A. This is a later 16k Korean-manufactured model with a single 28-pin ROM socket, which by default is populated with a 24-pin standard Color BASIC rom. What's the recommended way of upgrading to Extended Color BASIC? Should the normal 8k rom file flashed to an EPROM work fine? Quote Link to comment Share on other sites More sharing options...
MrDave Posted October 5, 2021 Share Posted October 5, 2021 You need a 16k (128) 28 pin eprom with ecb flashed to the lower 8k and color basic in the top half of the rom , then change those 128/64 jumpers to 128k (128/8 bit = 16k bytes) Quote Link to comment Share on other sites More sharing options...
swissarmytin Posted October 10, 2021 Share Posted October 10, 2021 On 10/4/2021 at 10:03 PM, MrDave said: You need a 16k (128) 28 pin eprom with ecb flashed to the lower 8k and color basic in the top half of the rom , then change those 128/64 jumpers to 128k (128/8 bit = 16k bytes) This worked perfectly! Thank you for the help. Quote Link to comment Share on other sites More sharing options...
MrDave Posted October 10, 2021 Share Posted October 10, 2021 6 hours ago, swissarmytin said: This worked perfectly! Thank you for the help. No problem, was one of my first hacks was to put a 32k rom with a switch on the high address so it was like 2 diffrent roms,so i had my own hacked version at the flip of a switch Quote Link to comment Share on other sites More sharing options...
towmater Posted October 12, 2021 Share Posted October 12, 2021 On 6/20/2021 at 9:46 AM, MarkO said: Since the MPIs let you have multiple Carts installed on your CoCo, and they are kind of Rare, there are modern version, the Mini MPI and Mega-Mini MPI available from Ed "Zippster" Snider, who also sells the CoCoSDC: https://thezippsterzone.com/ What can one do with an MPI? I'm assuming it can't be just for switching betweeen four games. Is there something like the TI voice pak that enhances compatible game carts? Quote Link to comment Share on other sites More sharing options...
MrDave Posted October 12, 2021 Share Posted October 12, 2021 Lol i had the cico speech sound cart way back.. very robot voice Quote Link to comment Share on other sites More sharing options...
+sm3 Posted October 13, 2021 Share Posted October 13, 2021 On 10/12/2021 at 9:26 AM, towmater said: What can one do with an MPI? I'm assuming it can't be just for switching betweeen four games. Is there something like the TI voice pak that enhances compatible game carts? With the MPI you can use multiple items at once, like a CoCo SDC along with a real floppy controller for instance. So not just about switching cartridges, but that is a nice feature as well because it saves wear and tear of the PCB slot. Quote Link to comment Share on other sites More sharing options...
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