So what did I buy? - Printable Version +- Discussion Forum for all things Microbee (https://microbeetechnology.com.au/forum) +-- Forum: Microbee Forum (https://microbeetechnology.com.au/forum/forum-1.html) +--- Forum: Microbee Hardware (https://microbeetechnology.com.au/forum/forum-6.html) +--- Thread: So what did I buy? (/thread-897.html)

So what did I buy? - tmuir - 18-03-2025 I've not received it yet, so I only have the photos from the sale. I'm hoping I don't regret buying this one, it looks to of had some upgrades done to it during it's lifetime. I do not yet have a power supply or a monitor sorted out for it yet and have no idea if it will work or not, but I'm sure it will give me a few fun nights. RE: So what did I buy? - CheshireNoir - 18-03-2025 Ooh! I know what that board is! it's a colour board! I have one in one of my Microbees. (If you had told me 5 years ago that I would be able to say "One of" in conjunction with the word "Microbee" I would have laughed at you.) Looks like it's fully populated with RAM so 56K. I don't know enough about that model to tell you more. Presumably some sort of floppy disk interface, but I can't see enough chips for that on the top "Core" board. John RE: So what did I buy? - ChickenMan - 18-03-2025 Yes thats a colour board, be careful plugging it back in. The 56k 'bee connected to an external floppy controller via the 50 way but not sure what that cable plugged into. RE: So what did I buy? - tmuir - 18-03-2025 Thanks, so not a floppy controller cable, maybe once I have it infront of me it will give more clues. On the plus side I was reminded that 'In the storeroom of doom' at one of our 'abandoned offices' at my work we may have a monitor old enough that the Microbee can connect to, so if I get time tomorrow I will have a look. The benefits of working for a largish company that over the last 10 years acquired a number of other companies and shut offices down but couldn't get rid of them due to long leases or critical equipment that can't be moved to other locations without a large investment of cash. RE: So what did I buy? - ChickenMan - 18-03-2025 Please put a sticker over the small window of the EPROM as even light can erase the code inside. Are you able to dump the code within the eprom also? RE: So what did I buy? - tmuir - 18-03-2025 Yes I have a modern EPROM programmer, also a few years ago I built the 'Retro Chip Tester' from the 8-bit museum that can also read most older EPROMs and I have coming in the mail new adapter boards that will let me even program some of the older EPROMs no longer supported on new equipment, then if I want to go really retro I can fire up my C64 and plug in my EPROM programmer I got for that when I was in primary school. I had already decided one of my first jobs would be to dump the EPROMs in case they die on me. As a primary school kid I used to get my dad to bring me home all the main boards from retired or broken industrial controllers and I still have the large collection of EPROMs I gathered from them including a few gold pinned 2708s and the pride of my collection 6 white ceramic, gold pinned Fujitsu 8516 EPROMs and my 1975 white ceramic, gold pinned NEC 8080AF. I used to collect 'retro electronics' back when it was just considered 'last years model' :-) RE: So what did I buy? - tmuir - 31-03-2025 I received the computer today. The mainboard is a 1248 Rev H. I have backed up the two EPROMs, the character ROM is good and RTC is reporting it as charrom.bin Microbee 128k Standard. The other ROM it can't identify as by it's checksum, but looking at the ROM dump as ASCI I can see it says 'MicroBee Disk Monitor c1983' the same as the 56kb.rom, but has a different checksum, so either its a different revision of the ROM or it has some data corruption in it as it didn't have a sticker over the window on the EPROM when I got it. So from what I can gather my computer is in a 16Kbit case, but is a 64K model with the MB1217 colour board fitted. Can anyone add anything else? RE: So what did I buy? - tmuir - 01-04-2025 I did a hex compare of my bin file to the 56kb.rom file and noticed a number of differences and at one point the 56k.bin data got one address out of alignment with my rom, so I'm thinking it's a different version, possibly an earlier version than the one in the repository. I've uploaded my ROM to my Google drive if anyone wants to download it to compare. https://drive.google.com/file/d/1r5u22-bxK_UYGstpY_RibNG1qzBHOtBG/view?usp=sharing RE: So what did I buy? - ChickenMan - 01-04-2025 The problem with a 56k Microbee is that they need an external FDC with Floppies attached to be a useful computer. At best, at the moment you can load BASIC off a tape via the Monitor, then load a game or program that runs out of basic also from Tape. A slow and painful process. That after you burn a new 56K boot rom (only one variety known to exist) and assume the Microbee is actually working. RE: So what did I buy? - tmuir - 01-04-2025 I was worried this would be the case. I don't suppose anyone has made an external controller that works with a Gotek or something like that?