WELCOME!

Welcome to my electronics projects site. If you're coming here from eBay, note that I'm trying to migrate from eBay to Tindie due to eBay's constantly rising fees. All items for sale on eBay are listed on Tindie too but with lower prices.

This is my store on Tindie! The sell links below direct you directly to specific listings on Tindie.

Introduction

This is a simple* website that shows some of my electronics projects. Some are for sale, others are not.

*Simple, yes. For two reasons. First, I'm not a web designer. Second, I want this web site to be viewable on the simplest of hardware. After all, most of these devices are meant to be used on very old computers.

Overview

My projects.

Finished boards

Gravis Ultrasound (GUS) ISA Sound Blaster MCA Sound Blaster Disney Sound Source
FOR SALE FOR SALE FOR SALE FOR SALE
Gravis ultrasound image 2 ISA Sound Blaster MCA Sound Blaster Disney Sound Source

Projects currently under development

MCA IDE HardSID with built-in SID emulator 386 ATX Motherboard
MCA IDE HardSID ATX 386 Motherboard

GUS

Status: FOR SALE ON TINDIE HERE. .

This is my reverse-engieered version of a replica of the Gravis Ultrasound PnP board. Yes, a replica of a replica (of a replica actually!).

Gravis ultrasound image 4 Gravis ultrasound image 4

At first I made them green. People complained and for the next batch I made them red. Also, this one doesn't have the mounting hole for the bracket like the red board. So the only way to fix this board to a bracket is using the screws on the joystick connector. I believe this was the way the original GUS PnP board was designed. On the red boards above I have added a mounting hole right above the LINE IN connector so that the board is more rigidly fixed to the chassis of the computer.

Gravis ultrasound image 4

A previous board with an older SIMM connector. This board also, doesn't have the WaveTable ROM soldered. I really don't know if that's ever needed. Doesn't seem to matter; most people want it anyway!

Gravis ultrasound image 1

ISA Sound Blaster

Status: FOR SALE ON TINDIE HERE. .

Here is a review of the card by DOS Storm.

Who doesn't love the ISA bus? This is an exact replica of the very first Sound Blaster sound card. In order to keep it 100 % compatible it has all the flaws and advantages of the original board. I have added a few small improvments though. These are the features:

The current version is 3.1:

ISA Sound Blaster

This is version 3.0. It was very similar to 3.1, just that it lacked the CD-ROM connectors. There are two versions (of both 3.0 and 3.1). Either with the 8051 DSP processor and the OPL2 (Yamaha YM3812/Y3014b) mounted in DIL sockets:

ISA Sound Blaster

Or with the 8051 and Yamaha chips chipset surface-mounted:

ISA Sound Blaster

Note that the C/MS (Game Blaster, or SAA1099) chips are always mounted in sockets; they simply don't exist in any other form as far as I know.

Here is an older version of the board that had slightly inferior amplification mode.

ISA Sound Blaster ISA Sound Blaster

Here is an even older version that is no longer for sale. I made this board by hand and prioritized ease of assembly to signal integrity. Also, the board did not support C/MS. Though it worked, it was rather sensitive to disturbances.

ISA Sound Blaster

MCA Sound Blaster

Status: FOR SALE ON TINDIE HERE. .

Here is the ADF File that you need in order to configure the card. You can also buy a floppy disk from Tindie with the ADF file if you so prefer.

Original Sound Blaster cards for the Micro Channel bus are quite hard to come by these days. This is my replica.

MCA Sound Blaster front

Here is a demo video of the card installed in a PS/2 Model P70 running Wolfenstein 3D.

This latest revision 2.0 has the following features:

That last feature is something cool that the Micro Channel bus allows but the ISA bus does not: the ability to route the output of the sound card to the internal PC speaker (and even between cards, if you want one card to record the output of another, for example). The internal audio is amplified and thus controlled by the volume pot in the back. Both audio outputs and the microphone bias are configurable in POS (i.e., what IBM calls the BIOS of a PS/2 Micro Channel system):

MCA Sound Blaster POS

For CD-ROM audio, there seems not to be a standard pinout for the connector so I added three connectors which should cover most cases. The pinouts are described on the backside of the card:

MCA Sound Blaster backside

This is a prototype of the 2.0 board that I had to fix up in order to get the internal audio to work:

MCA Sound Blaster

This is a previous version that is sold out.

MCA Sound Blaster

Disney Sound Source

Status: PROTOTYPE FOR SALE ON TINDIE HERE. .

Simple (resistor-DAC) sound cards for the parallel port can be found aplenty on eBay. This is my version that has several additional features:

It does require an extenal power supply, however. I've included a USB-C connector. Previous versions had USB-B, but people have requested a USB-C, so I replaced the USB-B with a USB-C.

Disney Sound Source Disney Sound Source

Here you can see that both the Disney Sound Source and the FTL Sound Adapter are detected correctly (depending on the mode switches that are described on the backside of the board):

Disney Sound Source Disney Sound Source

A few video demonstrations:

Dungeon Master using Disney Sound Source mode

Dungeon Master using FTL mode

Wolfenstein 3D using Disney Sound Source mode

Note that for some reason, ID Software only implemented sound effects using the Disney Sound Source; you needed an Adlib sound card in order to play MIDI.

Pinball Fantasies using regular Covox mode

This is a previous prototype that ended up having a few problems:

Disney Sound Source Disney Sound Source

This is a previous version that only had support for Disney Sound Source and a Covox DAC. It is the latest one to be sold and is currently sold out. I will not make more of these but wait until the new revision is finished before I produce more of these boards.

Disney Sound Source Disney Sound Source

This is an even older version that worked, but had tons of mistakes. I never put it up for sale:

Disney Sound Source Disney Sound Source

MCA IDE

Status: UNDER DEVELOPMENT.

Proprietary hard drives for the IBM PS/2 Micro Channel bus are hard to come by these days. So are regular IDE boards. This is my attempt to build an IDE board with the XT-IDE BIOS.

MCA IDE

This is an older revision where I had made a naive mistake that made it useless. It would only return correct data about 50 % of the time. Embarrassing! But during the development of the revision above I realized I could simplify things so much that I could even omit one of the level shifter chips I used on this version.

MCA IDE

During the development of this board I made a similar board for the ISA bus, just to prove to myself that I had a grasp of the workings of the IDE bus:

ISA IDE ISA IDE ISA IDE

HardSID

Status: UNDER DEVELOPMENT.

This is my attempt to build a replica of the HardSID with a built-in SID emulator. Naturally, the emulator can be switched off and an actual SID can be used in its stead.

HardSID

ATX 386 Motherboard

Status: UNDER DEVELOPMENT.