Search results

Thought I'd make it more retro computer specific. Here's one for the vintage mac crowd : Edit : After modifying the software a little so I could change the sample rate and x axis resolution, I ran the light and temperature sensor for a bit over an hour over sunset. The temperature probe was...

I've seen similar ones, but I don't think I've used one like that. What an absolutely weird way of setting the voltage! Nice to have low voltage AC.

I'm trying to remember what we had. I couldn't find a picture. The physics labs had... like, boxes with a recessed face and a big dial in the middle, like a 2" knob with a 3" flange (giggles). Same banana jacks. In the tech department they had much newer stuff and they had variable DC power...

Updatier - Added some details about the Contact Controller Plus to the same page above, which seems to use the same serial commands. Had to build little adapter for the power connector as it used a 5pin DIN connector.

They're old 68020s and 68881s. The XC means they're pre-validation, and the date codes look to be (late) 1985.

Update - Motors are at least in part controlled by command 0x47.

Made some good progress last night. I plugged in a Data Harvest FlowGo I'd picked up a while back. It didn't have any software with it and I hadn't done anything with it. I enjoy playing with old educational interface boxes - it was a big thing here in the UK in the 80s and 90s for teaching...

Yeah, that sounds like you're hitting your head on the speed limits due to the MC88920. It seems to be the first limit you bump your head on if you're not limited by the CPU.

Well now, looking at the source? That's cheating :ROFLMAO:

They could probably just use 74xx165s. All they're doing is checking the status of a matrix. I'd assume they're not planning on running every key to a pin.

This is probably of interest : https://github.com/elliotnunn/supermario/blob/master/base/SuperMarioProj.1994-02-09/OS/CudaMgr.a https://github.com/elliotnunn/supermario/blob/master/base/SuperMarioProj.1994-02-09/OS/EgretMgr.a Edit : I wasn't able to see an appropriate trap, even in the C...

The code here : https://github.com/cheesestraws/Force32/blob/main/xpram.c ... uses a trap to read / write XPRAM. I assume there is something similar for the general address space of the CUDA chip. Someone with perhaps inside knowledge might know what that trap is, or perhaps it is buried in...

Its connected on the logic board to a VIA by a basic bit bashed serial port from what I understand, so not memory mapped. So you could send any command to it you like by driving the pins on the VIA, which is memory mapped and well understood. What is weird is that there must be a memory dump...

As YMK says, you don't need to program the USB hub chip - it just does its thing. If you're doing this as a hobby thing and not a commercial enterprise, there isn't really any issue in programming the 32U4 over USB. Even for small volume sales it could be a feature for the homebrew community -...

They're pretty difficult to get hold of. People ask several times over more money for them than they do for 72pin simms. I've never managed to actually buy any, I was just lucky when a couple of machines had a few in already. I don't think I have enough for 1.5GB in a machine. Given the price...

They're nice! The AdaFruit documentation actually includes a schematic, so you could integrate the design, although it might be nice to ask them if it isn't just a straight up reference design from the datasheet (also below, and includes reference designs)...

Yeah, if you just moved resistors, you wont be running at 40MHz. Electrically the computer has a 40MHz setting on the resistors, but there isn't a ROM entry, so the computer just doesn't boot. It doesn't even chime. I suspect you're running at 33MHz. Like @JDW says, Clockometer will tell you.

As YMK says, you wouldn't implement a hub like that. If I was doing it on a budget, I'd perhaps buy a pre-existing board, remove the connectors or use extension cables internally and call it a day. Something like this might do as a USB 2.0 hub. Just search for CJMCU-204 on eBay or...

I've been able to run my 475 at up to 52MHz, but if you're already running at 40MHz I assume you have disconnected one of the pins on the 88920 and injected an external clock, or have a modified ROM? I'd need to know what exactly you've done to your machine to be able to answer for your specific...

At the end of the day, people in the hobby, I can't really complain. People have free will and no obligations. Work stuff, if it matters, either they need to be reminded why it has to happen and be given a deadline and milestones, otherwise it is getting reallocated to someone else. I've had it...