A compact ROM for Sinclair QL.
Use a 27c512 to load Minerva firmware and update your computer.
The Minerva ROM is also useful for diagnosing RAM problems.
Update with two version SMD & THT
SMD:
Components:
U1 AT27C512R-70JU
R1 10Kohm (0805)
R2 1Kohm (0805)
Q1 MMBT3904-T (SOT23)
J1 PIN HEADER or 1544210-2 (SIL CONTACT Y1 THROUGH HOLE)
THT:
Components:
U1 27C512
R1 10Kohm
R2 1Kohm
Q1 2N3904
J1 PIN HEADER or 1544210-2 (SIL CONTACT Y1 THROUGH HOLE)
Directory
Gerber : https://www.pcbway.com/project/shareproject/Minerva_ROM_fo_Sinclair_QL_644a941d.html
Gerber THT : https://www.pcbway.com/project/shareproject/Minerva_ROM_fo_Sinclair_QL_THT_Version_e9b613d4.html
IMG : Some pictures
Schematic: project outline
How program
Program the 27C512 memory before soldering it to the pcb, example with a plcc32-dip adapter and the TL866II, THT version not required the adapter.
The Minerva firmware can be found here:
https://dilwyn.qlforum.co.uk/qlrom/index.html
Once programmed you can solder the components such as the resistors and the transistor and finally the ROM and the pins.