Toots for codewiz@mstdn.io account

Written by Bernie on 2025-02-06 at 19:49

Anyway, my modded floppy drive works, but the eject button is black and doesn't align with the hole on the side of the Amiga 500 case.

Oh no! I'm back to using a hacked A500 with messy wires and exposed electronics! :amiga:

[#]commodore #amiga #retroocomputing #vintagecomputing

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Written by Bernie on 2025-02-06 at 19:43

Amiga floppy disk controllers use the original Shugart interface, whereas IBM PCs adopted a modified interface which uses a twisted ribbon cable to select the FDD unit.

https://old.pinouts.ru/HD/InternalDisk_pinout.shtml

[#]amiga #retrocomputing #vintagecomputing

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Written by Bernie on 2025-02-06 at 19:39

I modded a Sony MPF-920 T/B53) floppy drive to work on the Amiga.

This site has detailed instructions for several brands of PC FDDs:

https://jope.fi/drives/

[#]amiga #retrocomputing #electronics #vintagecomputing

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Written by Bernie on 2025-02-06 at 10:36

I opened the case to inspect the board, and after some dusting it looks great!

When I was still in middle school, I got an #Amiga 500 with the same board revision, and after a few years it was quite beaten up, with various upgrades and hacks soldered onto the board.

I don't know what happened to it, but in the end you could reliably crash the system by banging a fist on the desk 😆

[#]retrocomputing #commodore #vintagecomputing

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Written by Bernie on 2025-02-06 at 10:20

@janbeta, what do you think?

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Written by Bernie on 2025-02-06 at 10:19

Also annoyingly, this RetroPower PSU is rated exclusively for 230V AC outlets. Will I have to buy a different PSU if I want to take the Amiga 500 to the US (120V) or Japan (100V)?

Modern switching transformers usually tolerate a wide range of input voltages. So why this one won't? 💢

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Written by Bernie on 2025-02-06 at 10:10

Since the #Amiga 500 power supply was missing in the box, I ordered this RetroPower PSU:

http://www.retropowerpsu.com/?page=amiga

It's pricey, but I thought I could share it with the VIC 20, Plus 4 and #C64 which I'm currently repairing. Unfortunately it's not possible: the Amiga model lacks the 9VAC output needed by the 8-bit machines 😭

Why don't they sell a generic model with all the voltages, so you can simply swap the cable??

[#]electronics #retrocomputing #commodore

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Written by Bernie on 2025-02-06 at 09:57

Yesterday I powered this classic #Commodore #Amiga 500 for the first time in decades, and it still works flawlessly!

Well, aside from the floppy drive, which seems to have a flaky disk detection switch. It's a common issue with these drives, and I'm watching a couple of videos showing how to fix them.

[#]retrocomputing #vintagecomputing

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Written by Bernie on 2025-02-06 at 01:03

The EasyFlash 3 cartridge can replace the #C64 KERNAL with Jiffydos or other user-supplied ROMs.

Doing this without breaking software that swaps the KERNAL with RAM is tricky because the required HIRAM signal isn't routed to the Expansion Port.

Instead, the EasyFlash 3 uses a clever hack involving address snooping and briefly toggling the obscure Ultimax emulation mode at the beginning of a bus cycle.

Read a detailed explanation here:

https://skoe.de/kernal/kernal-cartridge.pdf

[#]retrocomputing #commodore

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Written by Bernie on 2025-02-05 at 08:45

Nine – seemingly impossible C64 demo

https://linusakesson.net/scene/nine/index.php

HN thread: https://news.ycombinator.com/item?id=42940553

[#]c64 #retrocomputing #demoscene

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Written by Bernie on 2025-02-02 at 15:25

I already had #SDCC 4.4.0 installed on my Fedora Linux laptop, but the recently released 4.5.0 further reduces code size and (presumably) also generates faster code.

You can grab the talk's slides here:

https://fosdem.org/2025/schedule/event/fosdem-2025-4899-the-small-device-c-compiler-targeting-z80-mos-6502-and-their-derivatives/

[#]retrocomputing #programming #fosdem

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Written by Bernie on 2025-02-02 at 15:20

I'm in the #retrocomputing room at #FOSDEM2025, watching a talk on #SDCC.

SDCC is an optimizing #C compiler targeting 8-bit CPUs and other small architectures.

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Written by Bernie on 2025-02-02 at 11:57

[#]Matrix 2.0 is a major upgrade, with a big focus on usability.

[#]FOSDEM2025 #FOSDEM

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Written by Bernie on 2025-02-02 at 11:54

Videocall demo using the next version of #Matrix / #Element running in docker.

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Written by Bernie on 2025-02-02 at 11:37

Wonderful project stats for #KiCad!

I've been using the pre-release of KiCad 9, and it's really nice 👍

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Written by Bernie on 2025-02-02 at 11:23

[#]Matrix adoption is growing fast! 😲

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Written by Bernie on 2025-02-01 at 09:59

And so, #FOSDEM2025 begins. #fosdem

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Written by Bernie on 2025-01-27 at 12:24

I detached the #Plus4 keyboard to test the power LED with a battery: it works.

I cleaned the contacts with isopropyl and plugged the flat cable back on the board and now... IT WORKS! 🎉

Was it just an oxidized contact? I'm not sure.

Anyway, the tuner video signal is very noisy. I wrote this short program to test sound output.

First time I play with the BASIC V3.5 multimedia commands, and it's awesome! :commodore:

[#]commodore #retrocomputing #vintagecomputing

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Written by Bernie on 2025-01-23 at 13:31

Last night I carefully opened the #Commodore wedge PSU with flat screwdrivers, but the interior is filled with a potting resin which is stuck to the box.

I measured +5V after the regulator, but it drops as soon as I connect the #Plus4 board.

If the board was shorted, the fuse would have blown. So I guess the regulator is unable to source more than a few milliamps.

I couldn't make further progress without tools. I'm literally working from my mother's kitchen! 🤓

[#]electronics #vintagecomputing

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Written by Bernie on 2025-01-23 at 13:13

In spite of its excellent conditions, this #Plus4 does not power up at all 😭

The AC fuse in the PSU and the DC one on the motherboard aren't blown, so my next suspect is the "wedge" power-supply.

These PSUs made by #Commodore in the '80s are known to fail often. Sometimes, they even output higher voltages on the +5V line which powers ALL the chips on the board! 😱

But this isn't the case: the power LED is steady off, and I measured near 0 volts on VCC pins.

[#]electronics #vintagecomputing

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