1581 Parts Kit

The 1581 Parts Kit allows you to pick and choose from most parts that are needed to build a 1581 replica.


The 1581 Parts Kit allows you to pick and choose from most parts that are needed to build a 1581 replica.

Note* RP1 is a 15 pin resistor pack. You may have seen other replica boards that split this resistor pack into 2 which is fine but I wanted to stay true to the original design. With that said, if anyone is able to actually find this resistor pack, please let me know. What you’re looking for is a 15 pin SIL bussed 1k resistor pack. Otherwise, that’s what R15 – R28 are for.


Qty Parts Value Device
1 U1 6502A 2MHZ IC – CPU
1 U2 23256 32K x 8 IC – ROM
1 U3 8K x 8 SRAM IC – SRAM
1 U4 WD1770 / WD1772 IC – FDC
1 U5 MOS 8520A IC – CIA
1 U6 74LS139 IC – Logic
1 U7 74LS00 IC – Logic
1 U9 74LS14 IC – Logic
1 U10 74LS93 IC – Logic
1 U11 7407 IC – Logic
1 U13 74LS241 IC – Logic
2 U8, U12 7406 IC – Logic
1 J1 (Only if using WD1770) Jumper Jumper
1 RP1 1K Resistor Pack
1 RP2 2.7K Resistor Pack
5 R1, R3, R9, R10, R11 47 Ohm 1/4 W 5% Resistor
1 R13 150 Ohm 1/4 W 5% Resistor
1 R12 620 Ohm 1/4 W 5% Resistor
17 R2, R4, R14 – R28 1K 1/4 5% RESISTOR0309/12
1 R5 2.7K 1/4 5% Resistor
14 C1 – C14 0.1uF Capacitor Ceramic
2 C18, C22 10uf Capacitor Electrolytic
1 C20 47uF Capacitor Electrolytic
1 C15 0.01uF Capacitor Ceramic
6 FB1 – FB6 Ferrite Bead Ferrite Bead
4 EMI1 – EMI4 100pF EMI Filter
1 Y1 16MHz Crystal
1 CN1 4 Pin Pin Header
1 CN2 34 Pin Pin Header
1 CR4 1N4148 / 1N914 Diode
1 LED2 Green LED3MM

3D Prints

1581 Case

These were found on some forum. I don’t remember who designed these and if anyone knows, I’d be happy to give credit. I did print these and the outcome looks very much like an original 1581 but it is slightly larger so not exactly a 1:1 replica.

1581 Isolation Shield

Not really a 3D print but for the sake of being complete, I thought I’d include this here. Would be easy enough to get some card stock and have a Cricut cut it out.

1581 Drive Mount Assembly

This piece is used to mount the floppy drive and attach it to the case. When using some generic PC drives such as the NEC FD1231T, it is necessary to raise this by a few MM which also means that the back part of the mount where all the holes are needs to be cut off since the case screw pillar is flush with this piece and raising it would prevent the case halves from coming together completely.

1581 Bottom Metal Bracket

What More Do I Need?

Let’s say you order the 1581 replica board and you also pick all of the add-ons. This is enough to get started for most but there are still some things you need to complete the build. Its not much but since the parts I’m going to mention here are a little more difficult to source or too expensive for me to stock for resale, you’ll need to procure them yourself.

  • Drive – Most 3 1/2 PC drives will work with some modification. I’ve been using the FD1231T NEC drive with success.
  • Power supply (same as 1541-II)
  • Serial Cable
  • Case – 3D Print

There are some other parts you may need to have fabricated or 3D print such as the bottom metal bracket and the drive mount assembly. Both of these are available as STL’s in the 3D Prints tab.

Also, just in case you have a W27C512 EEPROM, here’s the file you can program to that for U2


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