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 layers100 × 77.5 mm
LanguageCard
btb/LanguageCard45An Apple II Language Card. Based on a design by iz8dwf
- Size
- 100 × 77.5 mm
- Copper layers
- 2
- Thickness
- 1.53 mm
- Parts
- 42
- Nets
- 91
- Pads
- 318
- Tracks, vias
- 405, 22
- Pours
- 379
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 3 Aug 2022
- Updated
- 22 Sep 2023
Overview
LanguageCard is an open-source printed circuit board by btb, from the btb/LanguageCard repository on GitHub, published under the Apache-2.0 licence. It is a 2-layer board of 100 × 77.5 mm with 42 parts on 91 nets, routed with 405 tracks and 22 vias.
It is built around the 74LS175PC, 74LS32SC and 74LS86. Its parts include 11 ICs, 9 capacitors, 8 resistors, 4 diodes and 1 connector. It belongs with the retro computing and games boards of this library.
Main components
3
74LS175PC
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
74LS32SC
-- Logic Gates ROHSTexas InstrumentsLogic Gates
74LS86
DIP-14-20℃~+75℃ 10mA 2.7V 23ns@5V,15pF 2V 400mV 400uA 5V 74LS 800mV 8mA XOR Gate DIP-14 Logic Gates ROHSHITLogic Gates
README
README.mdLanguageCard
An Apple II Language Card. Based on a design by iz8dwf
Description
This is a simple "language card" for the Apple II and II+, which expands the system from 48K to 64K by means of 16K of RAM, switchable into the address space normally used by the system firmware. That's two banks of 4K in the D0-D8 space, and one bank of 8K in the E0-F8 space. The C0-C8 space is not touched.
It uses static RAM so there is no need for the ribbon cable connecting it to the logic board that the original language cards had.
Like the original language cards, it can also contain a chip that will be used to replace the F8 ROM on your logic board. Additionally, you can enable or disable this replacement ROM with a switch or jumpers. If configured correctly, you can put two different F8 ROM images on a single chip and switch back and forth between them.
Build Notes
R3, R4, R5
Use higher resistance for high-efficiency LEDs, e.g. 3.3K
U8 and U9
Any narrow 8KBx8 static RAM can be used. ex: 5C6408, Cy7C185, TC5588
U7
Optional. 2K or larger (E)EPROM for overriding the logic board's F8 ROM. Enable using SW1 or JP1.
SW1
Optional Toggle switch. Miniature, Sub-miniature, or Ultra-miniature, right angle, SPDT. (Sub, Ultra-mini use JP1 pads)
An SPST switch which only closes the outer two pin positions can also work if you short JP3.
To switch between two different F8 ROM images on a single 4K or greater chip, short JP2 and use a DPDT switch instead - must be a three-position center OFF switch (ON-OFF-ON) in order to disable the card ROM and use the logic board F8 ROM.
JP1
Enable and select which F8 ROM to use (if not using SW1)
| 6 | 5 |
| 4 | 3 |
| 2 | 1 |
No Jumpers: Card ROM disabled
Using a single ROM image:
JP2 open, Jumper on pins 1,3 (lower right): Card ROM enabled
Using two ROM images on a 4K or larger ROM:
JP2 shorted, Jumper on pins 1,3 (lower right) and 2,4 (lower left): Upper ROM image enabled (A11 high)
JP2 shorted, Jumper on pins 3,5 (upper right) and 4,6 (upper left): Lower ROM image enabled (A11 low)
Solder Jumper JP2
Short, and install DPDT switch (or use pair of jumpers as above) for ability to select two different F8 ROM images on a single (4K or larger) ROM.
Solder Jumper JP3
Short if using an SPST switch that only connects outer two pins
Parts
42| Qty | Value | Footprint | References |
|---|---|---|---|
| 8 | 100n | Capacitor_THT:C_Axial_L3.8mm_D2.6mm_P7.50mm_Horizontal | C2, C3, C4, C5, C6, C7, C8, C9 |
| 3 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1, R7, R8 |
| 3 | 560 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3, R4, R5 |
| 3 | 74LS08 | Package_DIP:DIP-14_W7.62mm | U2, U5, U6 |
| 2 | 3k3 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2, R6 |
| 2 | 6264 | Package_DIP:DIP-28_W7.62mm | U8, U9 |
| 1 | '64-'512 | Package_DIP:DIP-28_W15.24mm | U7Alt1 |
| 1 | 10μF | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C1 |
| 1 | 4148 | Diode_THT:D_A-405_P7.62mm_Horizontal | D1 |
| 1 | 74LS06 | Package_DIP:DIP-14_W7.62mm | U10 |
| 1 | 74LS175 | Package_DIP:DIP-16_W7.62mm | U3 |
| 1 | 74LS32 | Package_DIP:DIP-14_W7.62mm | U4 |
| 1 | 74LS86 | Package_DIP:DIP-14_W7.62mm | U1 |
| 1 | Apple II Expansion Bus | Apple2:Apple II Expansion Edge Connector | J1 |
| 1 | BANK 1 | LED_THT:LED_D5.0mm | D2 |
| 1 | DUAL ROM | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP2 |
| 1 | READ | LED_THT:LED_D5.0mm | D3 |
| 1 | ROM ENABLE | MySwitch:SW_Lever_2P2T_Alcoswitch_AE203SD1 | SW1 |
| 1 | ROM Enable | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical | JP1 |
| 1 | ROM F8 (2716/32) | Package_DIP:DIP-24_W15.24mm | U7 |
| 1 | SPST | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP3 |
| 1 | WRITE | LED_THT:LED_D5.0mm | D4 |
The 37 most common of 42 parts.
Questions
How big is the LanguageCard PCB?
It measures 100 × 77.5 mm and has 2 copper layers, 1.53 mm thick.
What parts does the LanguageCard use?
42 parts, built around the 74LS175PC, 74LS32SC and 74LS86. 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 LanguageCard KiCad files?
From the btb/LanguageCard repository on GitHub, at the commit this page was made from: the board is LanguageCard.kicad_pcb and its schematic LanguageCard.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the LanguageCard design in my own project?
Its repository publishes it under the Apache-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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