AdamT

Supporter of the makers, developers and retro community who are keeping the 8 bit spirit alive.Aspiring maker when I can find the skills and time.

[AdamT @AdamT117]

On the home straight with the #8bit AT65C02 testing. Alternative memory map via the programmable decoder looking good. A missing reset vector in my code had me for a while. Will tidy GitHub shortly and post my test code examples.
#RetroComputing

[AdamT @AdamT117]

An update to #AT65C02, ATOS! Combining EhBASIC,SMON,a shell-to create a powerhouse of native assembly, disassembly, trace stepping and BASIC.All on the friendly half finished V4 AT65C02,with LCD and enough blinkies to satisfy you its doing important things. #retrocomputing

[AdamT @AdamT117]

Im still here. Been messing with some disk drives as well as some PC-XT and Amstrad PPC640 stuff. As part of this created a python based GUI for the handy ArduinoFDC tool by David Hansel. 💾https://t.co/DfJY4zhC7P

[AdamT @AdamT117]

🕹️ Fixing my defective Famicom Family BASIC cart! Intro works, but entry to Game BASIC fails (IC2 RP2D129 likely bad?). Need a comparative rom dump. I assume 27C128 is a potential replacement fix. Tips for dumping/repair? #Famicom #RetroGaming #NESdev #ROMhacking

[AdamT @AdamT117]

Not sure im as excited by this as i should be. Feels like the hobbyist will need to spend more than they would have, for what, I'm not sure i see yet? https://t.co/i5gYjfttgy #Commodore #C64 via @timeextension64

[AdamT @AdamT117]

A bit embarrassing,my earlier posts on the #C64 MCL64 state limited/no cartridge support. When in fact it already does support!
I have added a better comparison in my repo,showing my improvement to specific carts,and deleted previous posts to correct. ✅ https://t.co/SvgUEizn0S

[AdamT @AdamT117]

@rwxdesigns Original code does provide acceleration,bypassing the bus and emulating RAM,Kernal&BASIC within the Teensy. Works well but limted to being off of the ancient https://t.co/hE0sZf4pW6 first step is getting the i/o,disk load,cart loading etc to be stable enough.

[AdamT @AdamT117]

Turned out nice,I'm done.Old composite mod removed,PPU leg restored,new TRRS video jack, general tidy.The PPUdigitizer by c0pperdragon,once fitted,took a bit of troubleshooting with the rgbtohdmi.Needed a new sampling profile and better PSU.Pixel perfect now and time to enjoy.

[AdamT @AdamT117]

Oh my,what am I looking at? Next up unravelling a Famicom composite mod. It works but troubles me. Resistors,outrageously sticky electrical tape,copper foil, jumper wires,is that a transitor? Shock&horror a cut leg! Any pointers to this is appreciated,so i can tidy up.

[AdamT @AdamT117]

Glad i did a check fit. Socketing the PPU is a no go even with low profile sockets. The reset slide mechanism on the famicom has very little clearance to the ICs.Lets hope the PPU is fine after the refit and digitizer install next, as I don't fancy desoldering again. 🤞

[AdamT @AdamT117]

Long time no post. Whats been going on? I fixed the ORIC.I had fried two RAM chips and the Logic IC for the RGB output.All good after replacement.Then I got distracted by some 1990s PC gaming setups, emerging from that now! Picking up the retroshield journey again at the moment.

[AdamT @AdamT117]

Picking up on the Oric-1 fix.Tragically I fried this not knowing about the danger of accidentally shorting the regulator, which lurks as a kill switch. Voltages in excess of 9v applied across the board. Started by removing all main ICs, and locating fried RAM...
#retrocomputing

[AdamT @AdamT117]

ORIC update. Tracing through the RGB and RAM logic to fix.I am using spare known good ICs until I can determine which main chips are blown.6522A ICs seems to be quite hard to find at a good price. Does the ORIC need the 'A' variant? Any compatible substitutes?
#retrocomputing

[AdamT @AdamT117]

@carlinhocr_ Great to see continued development. Keep at it, some cool additions. 👍

[AdamT @AdamT117]

Been a bit quiet here but rest assured I'm still tinkering. (1)Commited the 2114 SRAM tester to an UNO shield. (2)Broke an Oric-1, now fixing it. (3)Fixed an Acorn Atom, added some upgrades. (4)Fixed, broke and then bodge fixed a floppy drive latch mechanism.Evidence provided.

[AdamT @AdamT117]

Take the guess work out of 2114 SRAM trouble! There are existing Arduino test shields but didn't have one 😱 Also some code examples I tried checked ok without a 2114 in place? So made my own with some unnecessary user functions.Any mistakes let me know.https://t.co/ulvZEkoQjN

[AdamT @AdamT117]

Ok next up the MC14500B Retroshield. This is a 1-bit CMOS microprocessor launched by Motorola in 1977. 16 instructions, only 4 bits for jmps. I found this surprisingly difficult to get to grips with but created some simple code examples to get started. https://t.co/NO6fLVNfIu

[AdamT @AdamT117]

This month i have been having a look at the Motorola 6803 via the retroshield by https://t.co/9E93iWX8nW
I have struggled (more than usual) coding for this. Sometimes its just about finding a learning method or the guidance that 'fits'. This seems to be working for me...

[AdamT @AdamT117]

Erm, rather stupidly realised that single step (Trace) is already implemented in the SCP 8086 monitor for the 8088 Retroshield. So I have added a HEX loader to the ROM monitor. Now able to load simple programs into RAM and natively execute and debug them.