4 layers243.8 × 170.2 mm
2 layers73.7 × 81.1 mm
Video
dimitrit/pal1vdpPAL-1 Sprite Color Graphics Adapter
- Size
- 73.7 × 81.1 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 40
- Nets
- 107
- Pads
- 295
- Tracks, vias
- 26, 0
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 17 Sep 2022
- Updated
- 23 Aug 2024
Overview
Video is an open-source printed circuit board by dimitrit, from the dimitrit/pal1vdp repository on GitHub. It is a 2-layer board of 73.7 × 81.1 mm with 40 parts on 107 nets, routed with 26 tracks and 0 vias.
It is built around the 74LS574N, 74LS00SC and 74LS02PC, with the 74LS04PC and 74LS30PC among its other parts. Its parts include 15 capacitors, 10 ICs, 4 resistors, 3 connectors and 1 diode. It belongs with the interfaces and adapters boards of this library.
Main components
574LS574N
-0ns 0℃~+70℃ 1 2.6mA 20ns 24mA 28ns@5V,45pF 35MHz 4.75V~5.25V 74LS Series 8 D-Type Rising Edge Tri-State - Flip Flops ROHSRochester Electronics, LLCFlip Flops
74LS00SC
-0℃~+70℃ 15ns@5V,50pF 2 2.7V 2V 4 4.75V~5.25V 400uA 500mV 74LS 800mV 8mA NAND Gate - Logic Gates ROHSTexas InstrumentsLogic Gates
74LS02PC
DIP-140℃~+70℃ 15ns@5V,15pF 2 2.7V 2V 4 4.75V~5.25V 400uA 500mV 74LS 800mV 8mA 8mA NOR Gate DIP-14 Logic Gates ROHSonsemiLogic Gates74LS04PC
PDIP-140℃~+70℃ 4.75V~5.25V 6 6.6mA 74LS PDIP-14 InvertersonsemiInverters74LS30PC
PDIP-140℃~+70℃ 1 1.1mA 18ns@5V,50pF、20ns@5V,50pF 2.7V 2V 4.75V~5.25V 400uA 500mV 74LS Series 8 800mV 8mA NAND Gate PDIP-14 Logic GatesTexas InstrumentsLogic Gates
README
readme.mdPAL-1 Sprite Colour Graphics Adapter
The PAL-1 Sprite Colour Graphics Adapter is an expansion board for the PAL-1 system1, based on the Texas Instruments TMS9918A Video Display Processor (VDP)2 and was inspired by a Ciarcia's Circuit Cellar project3.
The TMS9918A VDP was used in video systems to provide data display on raster scanned colour television sets or monitors. The IC generates all necessary video, control, and synchronisation signals and also controls the storage and retrieval of display data in its own dedicated screen memory.
Note
The TMS9918A VDP generates a 525-line NTSC encoded colour video signal. While the TMS9928A VDP, which is intended for use with PAL video systems, is functionally compatible with the TMS9918A, it is not pin-for-pin compatible. Thus it is not possible to use the TMS9928A VDP in the PAL-1 Sprite Colour Graphics Adapter. Instead, users who do not have access to an NTSC TV or monitor are recommended to use AV to HDMI or AV to VGA converters as appropriate. Such converters are widely available from the usual e-commerce and auction web sites.
Acknowledgements
The SRAM circuitry is based on work by Tom LeMense and Dan Werner4,5.
PAL-1 and the PAL-1 logo used with kind permission of Liu Ganning.
References
- Liu Ganning, ‘PAL-1 Microcomputer User Manual’, 2020 http://pal.aibs.ws/assets/PAL_en.pdf [accessed 21 July 2022].
- ‘9900 TMS9918A/TMS9928A/TMS9929A Video Display Processors’ (Texas Instruments Incorporated, 1982) https://web.archive.org/web/20180717212934/https://emu-docs.org/VDP%20TMS9918/Datasheets/TMS9918.pdf [accessed 17 September 2022].
- Steve Ciarcia, ‘High-Resolution Sprite-Oriented Color Graphics’, Byte, 7.8 (1982), 57–80.
- Tom LeMense, ‘SRAM Replacement for TMS99x8 VRAM’, 2010 https://retrobrewcomputers.org/n8vem-pbwiki-archive/0/35845334/48860720/33053543/SRAM%20Replacement%20for%20TMS99x8%20VRAM.pdf [accessed 17 September 2022].
- Tom LeMense and Dan Werner, ‘Video Display Interface Board’, RetroBrew Computers Wiki, 2021 https://www.retrobrewcomputers.org/doku.php?id=boards:ecb:scg:start [accessed 17 September 2022].
Parts
40| Qty | Value | Footprint | References |
|---|---|---|---|
| 11 | 0.1uF | Capacitor_THT:C_Disc_D3.0mm_W1.6mm_P2.50mm | C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C14 |
| 3 | 74LS574 | Package_DIP:DIP-20_W7.62mm | U7, U8, U9 |
| 2 | 33pF | Capacitor_THT:C_Disc_D4.7mm_W2.5mm_P5.00mm | C11, C12 |
| 2 | 75 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R3, R4 |
| 1 | 0 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1 |
| 1 | 10.7386Mhz | Crystal:Crystal_HC49-U_Vertical | Y1 |
| 1 | 1N4148 | Diode_THT:D_DO-35_SOD27_P7.62mm_Horizontal | D1 |
| 1 | 220uF | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C15 |
| 1 | 22uF | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C13 |
| 1 | 2N3904 | Package_TO_SOT_THT:TO-92_Inline | Q1 |
| 1 | 470 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2 |
| 1 | 74LS00 | Package_DIP:DIP-14_W7.62mm | U2 |
| 1 | 74LS02 | Package_DIP:DIP-14_W7.62mm | U3 |
| 1 | 74LS04 | Package_DIP:DIP-14_W7.62mm | U4 |
| 1 | 74LS08 | Package_DIP:DIP-14_W7.62mm | U5 |
| 1 | 74LS30 | Package_DIP:DIP-14_W7.62mm | U1 |
| 1 | CY7C199 | Package_DIP:DIP-28_W7.62mm | U10 |
| 1 | Conn_01x02 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J3 |
| 1 | Conn_02x20_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x20_P2.54mm_Vertical | J1 |
| 1 | Conn_Coaxial | Video:RCA right angle phono | J2 |
| 1 | Inductor (bead) | Inductor_THT:L_Axial_L7.0mm_D3.3mm_P10.16mm_Horizontal_Fastron_MICC | L1 |
| 1 | Jumper_2_Open | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP2 |
| 1 | Jumper_3_Open | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | JP1 |
| 1 | LOGO | PAL-1:logo_eb | G*** |
| 1 | LOGO | LOGO | G*** |
| 1 | TMS9918A | Package_DIP:DIP-40_W15.24mm | U6 |
Questions
How big is the Video PCB?
It measures 73.7 × 81.1 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Video use?
40 parts, built around the 74LS574N, 74LS00SC, 74LS02PC and 74LS04PC. 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 Video KiCad files?
From the dimitrit/pal1vdp repository on GitHub, at the commit this page was made from: the board is video/video.kicad_pcb and its schematic video/video.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Video design in my own project?
Its repository states no licence, so its author keeps all rights: ask dimitrit before reusing the design.
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