Shared Projects

This is part of the PS1 Flash Bios project.

It’s an easy way to swap the PS1’s bios. All PS1 revisions with 32 pin BIOS are supported.

Order this board in 0.8mm thickness!

The (B) variant consists of three boards. The (B1) board is the circuit board that is soldered into the PS1. There is a 32 pin connector on it. The (B2) board is then the counterpart to it. The matching 32-pin connector is on the underside and the SST39VF040 TSOP memory is on top. The memory is pluggable and can be removed and re-flashed externally at any time. For external flashing, there is also the (B3) board, which is intended for the TL866 programmer and has the appropriate socket.

Attention 1!

The B variant cannot be used together with the PS1Digital, as the boards are too high and do not fit under the PS1Digital Board.

Attention 2!

The DF12 (3.0) -32DS-0.5V is no longer manufactured. You have to find old stocks or an alternative of the same construction.

For the (B) variant you need:

• PS1_Flash_Bios_(B1) board
• or PS1_Flash_Bios(B1)without_castellation board
• PS1_Flash_Bios_(B2) board
• PS1_Flash_Bios_(B3) board
• SST39VF040 Flash IC
• DF12(3.0)-32DP-0.5V
• DF12(3.0)-32DS-0.5V is no longer produced!
• 10K resistor 0603 (or solder bridge)
• two 1x16 pinheaters

without_castellation: The version “without castellation” has no castellated vias. These have to be cut yourself. Some board manufacturers charge extra for castellation.

This is part of the PS1 Flash Bios project.

It’s an easy way to swap the PS1’s bios. All PS1 revisions with 32 pin BIOS are supported.

Order this board in 0.8mm thickness!

The (B) variant consists of three boards. The (B1) board is the circuit board that is soldered into the PS1. There is a 32 pin connector on it. The (B2) board is then the counterpart to it. The matching 32-pin connector is on the underside and the SST39VF040 TSOP memory is on top. The memory is pluggable and can be removed and re-flashed externally at any time. For external flashing, there is also the (B3) board, which is intended for the TL866 programmer and has the appropriate socket.

Attention 1!

The B variant cannot be used together with the PS1Digital, as the boards are too high and do not fit under the PS1Digital Board.

Attention 2!

The DF12 (3.0) -32DS-0.5V is no longer manufactured. You have to find old stocks or an alternative of the same construction.

For the (B) variant you need:

• PS1_Flash_Bios_(B1) board
• or PS1_Flash_Bios(B1)without_castellation board
• PS1_Flash_Bios_(B2) board
• PS1_Flash_Bios_(B3) board
• SST39VF040 Flash IC
• DF12(3.0)-32DP-0.5V
• DF12(3.0)-32DS-0.5V is no longer produced!
• 10K resistor 0603 (or solder bridge)
• two 1x16 pinheaters

without_castellation: The version “without castellation” has no castellated vias. These have to be cut yourself. Some board manufacturers charge extra for castellation.

This is part of the PS1 Flash Bios project.

It’s an easy way to swap the PS1’s bios. All PS1 revisions with 32 pin BIOS are supported.

Order this board in 0.8mm thickness!

The (B) variant consists of three boards. The (B1) board is the circuit board that is soldered into the PS1. There is a 32 pin connector on it. The (B2) board is then the counterpart to it. The matching 32-pin connector is on the underside and the SST39VF040 TSOP memory is on top. The memory is pluggable and can be removed and re-flashed externally at any time. For external flashing, there is also the (B3) board, which is intended for the TL866 programmer and has the appropriate socket.

Attention 1!

The B variant cannot be used together with the PS1Digital, as the boards are too high and do not fit under the PS1Digital Board.

Attention 2!

The DF12 (3.0) -32DS-0.5V is no longer manufactured. You have to find old stocks or an alternative of the same construction.

For the (B) variant you need:

• PS1_Flash_Bios_(B1) board
• or PS1_Flash_Bios(B1)without_castellation board
• PS1_Flash_Bios_(B2) board
• PS1_Flash_Bios_(B3) board
• SST39VF040 Flash IC
• DF12(3.0)-32DP-0.5V
• DF12(3.0)-32DS-0.5V is no longer produced!
• 10K resistor 0603 (or solder bridge)
• two 1x16 pinheaters

without_castellation: The version “without castellation” has no castellated vias. These have to be cut yourself. Some board manufacturers charge extra for castellation.

BOM

Contact me if there are questions.

About a year ago, I have built a small AM radio transmitter (project AMTrans) which was supposed to boadcast audio content over a short range. Although this transmitter does work in principle, its range leaves much to be desired. My idea was to combine this transmitter with a leftover DVBT antenna which I wanted to convert into an active transmission antenna for radio signals.

Unfortunately, I am not exactly an expert in high frequency electronics which is almost voodoo to me. My approach is naively relying on common sense combined with a healthy touch of “bigger is better” :-). The design is based on the dual opamp approach which I have used before e.g. in my curve tracer project. One opamp buffers the central tap of a voltage divider which establishes the positive and negative rail for the second opamp, the one which does the actual amplification.

It turned out that this amplifier circuit interfered with my transmitter and saturated its coupling capacitor over time. Resistor R5 lets this accumulating charge trickle off. I got this idea when I remembered the grid leak of ancient vacuum tube based radio technology. A grid leak is a high-ohmic resistor which either bypasses the coupling capacitor of the grid or connects the grid to the cathode. Both ways the grid’s bias is stabilized by draining those electrons which inside the tube are heading for the anode but accidentally hit the grid. Without the grid leak, a negative charge would accumulate on the grid which would negatively affect the functioning of the tube :-).

The original DVBT antenna was driven by a 6V power supply and at first I intended to reuse this. However, my AD8034 opamps are specified for 24V operation, so why not ramp up the output of the antenna a little bit (which is the bigger - is - better part)? So I ordered a linear 24V power supply from AliExpress and used this instead.

Luckily there is room enough in the housing to solder a two-pin connection header onto the antenna lug. This way, the PCB can be just plugged onto this header and screwed down safely like the original board.

After all, this naive approach to amplfy the antenna signal seems to work. I can receive the radio signal inside a room and even in the adjacent ones. Of cause I have to find a spot without noise from all those switching regulators, but neverthless I call this design a success :-).

Schematics:

3D Model:

ADC for raspberry pi’s. See the Hackaday project for details.

Board for v4 of the filament width sensor.

ISA 8-Bit Ethernet Controller is an open source network interface controller (NIC) card, designed specifically to be used in computers with 8-bit only ISA (aka XT) bus, such as IBM PC, IBM PC XT, various PC/XT compatibles, for example Micro 8088 system. It is based on Realtek RTL8019 ethernet controller and is NE2000-compatible.

This is an adapter for the Nintendo Twin Famicom expansion port A. It is compatible with NES and SNES controllers, plus the NES Zapper lightgun with the 2P NES port.

Pins needed:

22 or 28 of these

https://www.digikey.ca/en/products/detail/3149-2-00-15-00-00-08-0/ED1183-ND/436969

9 or 15 of these

https://www.digikey.ca/en/products/detail/170-202-170L003/89SE-ND/1164238

Check the GitHub page for complete info of the project:

https://github.com/jeffqchen/twindiamond

Smart Bin System

Digital potentiometer breakout board for Z221 - pairs with Vset 2.0

Controller for DP1.0

Small FSM for a 2-bit counter using a 555 timer to generate the clock.

4MB extender board for ROMY

http://github.com/reinauer/amiga-romy