retr0brite not so right?

On 04/08/10 18:54, Tony Duell wrote: A680... that's the RISC iX box, isn't it?? Adrian Graham (witchy) sent me some hi-res scans of the PCB ages ago. I've been meaning to make a PCB from them, but I need to look into ways to get a good B/W image of the track layout. Thresholding the image doesn't quite work... Ugh, nasty. Some people (not me) would frame it and put it on the wall...... A ROM monitor instead of BASIC, and an edge-connector with all the bus lines on it :) Although the AIM65 bucks that trend; AIUI it has a built in ROM BASIC *and* the monitor, and the Multitech Micro-Professor certainly had a BASIC ROM available. There's a breaking point though. When I'm programming PLDs, I generally don't give a hoot how big the logic equation set becomes (as long as it fits into the PLD). If I'm wiring up hardware, the "must fit on a Roth Elektronik Eurocard-size padboard" rule applies. I try to avoid straddling projects across multiple pad-boards; my 6502 card can boot standalone, but it's not much use without the UART or some form of hex keyboard and display (TIL311 to the rescue!). [BBC micro] Another point I missed :) "Google is your friend" :) I had it in my Master 128 (it filled the room with smoke) and in a Solartron 7150Plus 6-digit bench DMM. The filter module in the 7150 actually caught fire (!) and I called the company and asked if they knew why it might do that, and if they had any distributors who'd sell 1-offs (RS wanted ?49 and in any case were downright rude last time I tried to place an order with them). Their response: "We'll send you another filter module." The 7150+ is still in service -- I've got a full service manual, but $DEITY help me if the Hitachi 68B03 mask-ROM micro on the analog board jacks it. Mask ROM and it's soldered to the board. Ewwww. If it wasn't soldered down I'd stick it in a breadboard and dump its contents to disc... (it has a 'test mode' which maps an external EPROM into the reset vector, and moves the internal ROM higher up in the memory map) One of the few occasions when shotgun replacement is justified. The other one is when you've got a machine on the bench which is showing symptoms of Capacitor Plague. In that case I'd sketch out part locations (and locations/values of nearby parts), remove the old parts, and give the surrounding area a good soak in flux remover (or IPA) and a decent scrub. Maybe a trip in the dishwasher if it was particularly mucky... Then the new parts go in, and any track breaks are repaired. At least the hot-air gun makes it (reasonably) easy to remove the SMDs. A pre-heater would make it even easier, but unfortunately the budget won't stretch that far at the moment... -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/