4 layers337.6 × 105.7 mm
ISA CGA
hkzlab/CGA_Redux
The Color Graphics Adapter Redux board is a more or less faithful clone of the original IBM CGA, based on the original schematics
170 parts56
2 layers162.6 × 99.1 mm
Ql trump v2 disk interface
alvaroalea/QL_Trump2_clone8DIsc Interface for the Sinclair QL computer
- Size
- 162.6 × 99.1 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 64
- Nets
- 149
- Pads
- 513
- Tracks, vias
- 2,124, 138
- Pours
- 6
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 1 Oct 2022
- Updated
- 28 Feb 2026
Overview
Ql trump v2 disk interface is an open-source printed circuit board by alvaroalea, from the alvaroalea/QL_Trump2_clone repository on GitHub. It is a 2-layer board of 162.6 × 99.1 mm with 64 parts on 149 nets, routed with 2,124 tracks and 138 vias.
It is built around the 27C256-17/J, 74HC04D and 74LS157PC, with the 74LS175PC among its other parts. Its parts include 20 capacitors, 18 ICs, 10 resistors, 10 diodes and 5 connectors. It belongs with the interfaces and adapters boards and the FPGA and CPLD boards of this library.
Main components
427C256-17/J
-0℃~+70℃ 256Kbit 4.5V~5.5V EPROM Parallel Port (Parallel) - Non-Volatile Memory (ROM)Microchip TechnologyNon-Volatile Memory (ROM)
74HC04D
SOP-14-40℃~+125℃ 1 1.5V~4.2V 1.9V、3.7V、5.2V 100mV、400mV、400mV 14ns@6V,50pF 2V~6V 2uA 5.2mA 5.2mA 500mV~1.8V 6 74HC SOIC-14 Inverters ROHSNexperiaInverters
74LS157PC
PDIP-160℃~+70℃ 4.75V~5.25V Single Supply PDIP-16 Signal Switches, Multiplexers, Decoders ROHSTexas InstrumentsSignal Switches, Multiplexers, Decoders74LS175PC
PDIP-160℃~+70℃ 1 10ns 18mA 25ns@5V,15pF 30MHz 4 4.75V~5.25V 5ns 74LS Series Asynchronous Complementary type D-Type Reset Rising Edge PDIP-16 Flip Flops ROHSTexas InstrumentsFlip Flops
README
README.mdSINCLAIR QL Trump Card V2 disk interface
(C) 2022 Alvaro Alea Fernandez
License under: CERN Open Hardware Licence Version 2 - Strongly Reciprocal
https://ohwr.org/cern_ohl_s_v2.txt
Available in the market in 4 ways, 0K, 256Kb/ACE, 512Kb, 768Kb and Treo (256Kb aditional).
Only 0Kb has been tested.
Check the readme in the GAL folder, up to now, I only be able to make it work without RAM.
Technical Info
Components to use
4040
We found that not all manufacturer made CD4040 or 74HC4040 in the same way, and some made counter with rise-edge of clock, and some with falling-edge.
The trump card need falling edge or will mess with the refresh cycle and do not work.
The eprom/gal programer TL-866 II+ has a function to test TLL chips, but fail to detect it and consider valid both variants.
We have include the file 4040-test.lgc with a custom test that when load on the programmer allow to detect valid 74HC4040 variants. (best to use 74HC4040 that CD4040)
RAM Chips
Trump Card use 514256 Ram chips, this is 4bits x 256K (1Mbit) Dinamic RAM.
Trump Card use a special refresh mode of this chips called hidden refresh, but not all manufacturer implement in tha same way.
Has been reported that Texas Instrument TMS44C256 are not valid and will cause errors on boot.
Motorola (MCM514256) Siemens (HYB514256) and OKI (MSM514256) has been reported to work
Toshiba (TC514256) and GoldStart (GM71C4256) al also valid acording to datasheet, but not tested.
The trump card schematic used 0 wait state ram, even in the refresh cycle, and for that speed of the dram shall be between 70 and 100ns, 120ns or slower are not valid.
HOLD
Parts
64| Qty | Value | Footprint | References |
|---|---|---|---|
| 10 | 1N4148 | Diode_THT:D_DO-35_SOD27_P10.16mm_Horizontal | D1, D2, D3, D4, D5, D6, D7, D8, D9, D10 |
| 9 | 330n | Capacitor_THT:C_Disc_D7.5mm_W4.4mm_P5.00mm | C1, C10, C12, C17, C18, C19, C20, C21, C22 |
| 6 | M514256A | Package_DIP:DIP-20_W7.62mm | U7, U8, U9, U10, U11, U12 |
| 5 | 33uF/16V | Capacitor_THT:CP_Axial_L11.0mm_D5.0mm_P18.00mm_Horizontal | C14, C16, C23, C24, C25 |
| 4 | 100p | Capacitor_THT:C_Disc_D7.0mm_W2.5mm_P5.00mm | C2, C3, C4, C5 |
| 4 | 680 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R7, R8, R9, R10 |
| 3 | Conn_01x01 | TestPoint:TestPoint_THTPad_D1.5mm_Drill0.7mm | J3, J4, J5 |
| 2 | 2K7 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R5, R6 |
| 2 | 330 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2, R3 |
| 2 | 330n | Capacitor_THT:C_Disc_D5.1mm_W3.2mm_P5.00mm | C13, C15 |
| 2 | 74HC04 | Package_DIP:DIP-14_W7.62mm | U3, U15 |
| 2 | 74LS157 | Package_DIP:DIP-16_W7.62mm | U5, U6 |
| 2 | GAL16V8 | Package_DIP:DIP-20_W7.62mm | U1, U2 |
| 1 | 1K8 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1 |
| 1 | 27C256 | Package_DIP:DIP-28_W15.24mm | U14 |
| 1 | 74HC4040N | Package_DIP:DIP-16_W7.62mm | U4 |
| 1 | 74LS175 | Package_DIP:DIP-16_W7.62mm | U16 |
| 1 | 74ls175 | Package_DIP:DIP-16_W7.62mm | U17 |
| 1 | 7805 | Package_TO_SOT_THT:TO-220-3_Horizontal_TabDown | U18 |
| 1 | 820 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R4 |
| 1 | 8Mhz | Crystal:Crystal_HC18-U_Vertical | Y1 |
| 1 | Conn_02x17_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x17_P2.54mm_Horizontal | J2 |
| 1 | FDC_WD1772 | Package_DIP:DIP-28_W15.24mm | U13 |
| 1 | QL_SLOT_DIN41612_CARD | Connector_DIN:DIN41612_Q_2x32_Female_Horizontal_THT | J1 |
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Questions
How big is the Ql trump v2 disk interface PCB?
It measures 162.6 × 99.1 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Ql trump v2 disk interface use?
64 parts, built around the 27C256-17/J, 74HC04D, 74LS157PC and 74LS175PC. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Ql trump v2 disk interface KiCad files?
From the alvaroalea/QL_Trump2_clone repository on GitHub, at the commit this page was made from: the board is ql_trump_v2_disk_interface.kicad_pcb and its schematic ql_trump_v2_disk_interface.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Ql trump v2 disk interface design in my own project?
Its repository states no licence, so its author keeps all rights: ask alvaroalea before reusing the design.