How To Restore A Musical Amiga

December 24, 2022 by Bryan Cockfield 21 Comments

Despite the huge strides in computing power and functionality that have been achieved in the past few decades, there are still some things that older computers can do which are basically impossible on modern machines. This doesn’t just include the ability to use older hardware that’s now obsolete, either, although that is certainly a perk. In this two-part restoration of an Amiga 500, [Jeremy] shows us some of these features like the ability to directly modify the audio capabilities of this retro machine.

The restoration starts by fixing some damage and cleaning up the rest of the machine so it could be powered up for the first time in 30 years. Since it was in fairly good shape he then started on the fun part, which was working with this computer’s audio capabilities. It includes a number of amplifiers and filters in hardware that can be switched on or off, so he rebuilt these with new op-amps and added some new controls so that while he is using his MIDI software he can easily change how it sounds. He also restored the floppy disk drives and cleaned up the yellowing on the plastic parts to improve the overall appearance, as well as some other general improvements.

These old Amigas have a lot going for them, but since [Jeremy] is a musician he mostly focused on bringing back some of the musical functionality of his childhood computer, although he did build up a lot of extra features in this machine as well. These types of audio circuits are not something found in modern computers, though, so to get a similar sound without using original hardware you’ll need to build something like this NES audio processing unit programmed in Verilog.

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A Love Letter To My Lost Amiga

December 20, 2022 by Jenny List 140 Comments

My first love was a black wedge. It was 1982, and I had saved up to buy a Sinclair ZX81. That little computer remains the only one of the huge number that I have owned over the years about which I can truly say that I understood its workings completely; while I know how the i7 laptop on which this is being written works I can only say so in a loose way as it is an immensely complex device.

Computing allegiance is fickle, and while I never lost an affection for the little Sinclair I would meet my true electronic soulmate around eight years later as an electronic engineering student. It no longer graces my bench, but this was the computer against which all subsequent machines I have owned would be measured, the one which I wish had not been taken from me before its time, and with which I wish I could have grown old together. That machine was a Commodore Amiga, and this is part love letter, part wistful musing about what could have been, and part rant about what went wrong for the best desktop computer platform ever made. Continue reading “A Love Letter To My Lost Amiga” →

You Can Now Bootstrap Your Amiga Without A Floppy With This One Weird Trick

October 28, 2022 by Lewin Day 12 Comments

Traditionally, most Amigas were intended to boot from a floppy disk. . An Amiga can readily make its own boot floppy, but only once it’s already booted up. If you don’t have a floppy ready to go, you’re out of luck, as PCs can’t readily make them for Amigas. [Roc] whipped up the amigaXfer bootstrapping method to solve this very problem.

Shorting a couple of pins together can unlock a serial debug mode that can be used for bootstrapping the machine.

Available on Github, the amigaXfer tool is able to perform several tasks with an Amiga via its serial port. The Amiga must first be turned on while plugged into another computer running amigaXfer via serial connection. When the Workbench floppy prompt comes up, the CrashEntry feature on amigaXfer should be triggered, and the BERR and GND pins on the Amiga’s 68000 CPU should be connected just for a split second, triggering the Amiga to go into a special serial debug mode. This enables amigaXfer to take control, allowing a disk to be formatted and written with a debug bootblock, and this disk can then be used to boot the Amiga without the need for the hack.

It’s a nifty way to get your Amiga up and running if you’ve just bought it off eBay and it didn’t come with any disks. From here, you can use amigaXfer to load other programs onto the Amiga via the same serial cable you used for the bootstrapping process, too. The hack isn’t limited to just the Amiga 500, either. It should work on a range of machines, including AmigaOS versions 1.x, 2.x, and 3.x.

Unlike the Commodore 64, we probably won’t see brand new replica Amigas anytime soon, but we can dream. As always, if you’ve got ’em, send your hottest Amiga projects into the tipsline!

Retrocomputing, Time To Hang Up The Original Hardware?

June 28, 2022 by Jenny List 57 Comments

For those of us with penchant for older technology, there’s something special about operating with older hardware. Whether it’s a decades-old camera, a vintage keyboard, or a home computer from the 1980s, the modern equivalent just doesn’t quite compare. But working with older parts definitely isn’t for the faint-hearted, as the passage of time has taken its toll on their reliability. Is it time to recognize that the supply of replacement vintage parts is not infinite, and to switch from using original hardware to more modern alternatives? [Retro Recipes] poses this question after a particularly difficult-to-find Amiga fault, and discusses it while evaluating a replacement Amiga made entirely from modern parts.

The new Amiga in question is a recreation of an A1200 with a re-manufactured case and keyboard, and the guts of an A500 Mini retro console taking the place of the Commodore board. He goes through the process of making an Amiga hard drive image on a USB drive using the image from his original drive in his teenage years, and boots it both on the 500 Mini based machine and on the UAE emulator on a Mac laptop. You can follow him in the video below the break.

We can see the logic in treating original hardware as a precious resource that’s not to be run up for fear of breaking it, but by the same token we’re still standing by that first sentence. But should the enjoyment of an older machine be limited only to those who have an original? We think not, so if enjoying an Amiga without an Amiga can be as good as the real thing then we’re all for it.

Of course, for those whose original Amigas have already broken, there are other ways to bring them back.

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Odd Inputs And Peculiar Peripherals: A Joystick Like They Used To Make

June 15, 2022 by Jenny List 6 Comments

With the rise of the gamepad courtesy of several generations of game consoles, the joystick has become an almost forgotten peripheral, sidelined into the world of flight simulators with its design tending towards copying that of aircraft joysticks. Classic joysticks from the 8- and 16-bit eras were far more workaday devices, more suitable for Space Invaders than Microsoft Flight Simulator, and it’s one of these that [Rob Smith] has recreated in 3D printed form.

The design he’s come up with bears a strong resemblance to the Zipstik, a classic stick that he already owned. It’s a fairly simple device that uses microswitches for all contacts, and is thus very tough. He’s produced a 3D-printed shaft but didn’t trust its strength, so copied the original by using a metal shaft with a pair of circlips. We remember our Zipstik as having a steel shaft; he replaces that with aluminium. A handy jig and a hacksaw allows him to create grooves for circlips, resulting in a sturdy ZipStik clone that should satisfy any retro gamer.

The stick is wired for an Amiga and includes a 555-based rapid-fire circuit, but that’s not the end of the electronics as he’s also created a USB interface for Amiga joysticks to go with it. Not everyone has a classic machine, so now everyone can enjoy the retro peripheral experience! Both builds can be seen in the videos below the break.

This isn’t the first Amiga joystick we’ve brought you, but it’s more sophisticated than some previous designs.

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The Return Of SCSI

March 2, 2022 by Al Williams 67 Comments

There was a time when high-performance disk drives used SCSI — the Small Computer System Interface — and everything else was kid stuff. Now, advanced forms of SCSI are still around but there are other high-performing disk interfaces, too. But some old gear really loves their classic SCSI ports, and [Adrian] decided to try hooking some of them up to some modern computers. You can see how he did in the video below.

The key to the attempt is a USB to SCSI adapter which was unusual but not unheard of, and [Adrian] came across one from 1999. Of course, you have to wonder if a modern computer will support the device or will be able to load the drivers from the old CD.

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A circuit board with a memory chip in a socket, and many memory chips in foam

Simple DRAM Tester Built With Spare Parts

February 27, 2022 by Chris Wilkinson 13 Comments

Some of the most popular vintage computers are now more than forty years old, and their memory just ain’t how it used to be. Identifying bad memory chips can quickly become a chore, so [Jan Beta] spent some time putting together a cheap DRAM tester out of spare parts.

This little tester can be used with 4164 and 41256 DRAM memory chips. 4164 DRAM was used in several popular home computers throughout the 1970s and 1980s, including the Apple ][ series, Commodore 64, ZX Spectrum and many more. Likewise, the 41256 was used in the Commodore Amiga. These computers are incredibly popular in the vintage computing community, and its not uncommon to find bad memory in any of them.

With an Arduino at its core, this DRAM tester uses the most basic of electronic components, and any modest tinkerer should have pretty much everything in stock. The original project can be found here, including the Arduino code. Just pop the suspect chip into the ZIF socket, hit the reset switch, and wait for the LED – green is good, and red means it’s toast.

It’s a great sanity check for when you’re neck deep in suspect DRAM. A failed test is a sure sign that the chip is bad, however the tester does occasionally report a false pass. Not every issue can be identified with such a simple tester, however it’s great at weeding out the chips that are definitely dead.

If you’re not short on cash, then the Chip Tester Pro may be more to your liking, however it’s hard to beat the simplicity and thriftiness of building your own simple tester from spare parts. If you’re a little more adventurous, this in-circuit debugger could come in handy.

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