https://github.com/jbilander/reagnus-megachip
A ReAgnus MegaAChip PCB that takes a Gowin FPGA with embedded PSRAM, a PLCC-84 plug and FET level shifters.
https://github.com/jbilander/reagnus-megachip
Last synced: 6 months ago
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A ReAgnus MegaAChip PCB that takes a Gowin FPGA with embedded PSRAM, a PLCC-84 plug and FET level shifters.
- Host: GitHub
- URL: https://github.com/jbilander/reagnus-megachip
- Owner: jbilander
- License: cc-by-sa-4.0
- Created: 2022-08-22T19:29:49.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2025-01-27T17:33:15.000Z (over 1 year ago)
- Last Synced: 2025-03-20T23:51:20.540Z (over 1 year ago)
- Language: Verilog
- Homepage:
- Size: 32.7 MB
- Stars: 25
- Watchers: 7
- Forks: 0
- Open Issues: 1
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Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ReAgnus-MegAChip
A ReAgnus MegaAChip PCB that takes a Gowin FPGA with embedded PSRAM, a PLCC-84 plug and FET level shifters.
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THIS IS WORK IN PROGRESS, HARDWARE IS VERIFIED WORKING. FIRMWARE YET TO BE DEVELOPED. BUILD AT YOUR OWN RISK.
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For hi-res pics goto the hi-res folder in pics
https://github.com/jbilander/ReAgnus-MegAChip/tree/main/pics/hi-res
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BOM Rev. 2C
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Designator | Name/Value | Package | Notes
-|-|-|-|
U1 | Gowin FPGA GW1NR-UV9LQ144PC6/I5 | LQFP-144 | FPGA - Field Programmable Gate Array, 8640 LE, 121 I/O, Embedded 64Mbit 16-bit PSRAM
[GW1NR-UV9LQ144PC6/I5](https://www.mouser.com/ProductDetail/192-1NRUV9LQ144PC6I5)
U2 | Voltage Regulator 3.3V,
LM1117-3.3 or
AMS1117-3.3 | SOT-223 | 3.3V 1A Low Drop-Out (LDO) Voltage regulator. https://www.aliexpress.com/item/32869037691.html
U3 | Voltage Regulator 4.3V, TPS73643DBVR or
ABLIC S-1132B43-M5T1U | SOT-23-5 | 4.3V LDO Voltage Regulator
[TPS73643DBVR](https://www.mouser.com/ProductDetail/595-TPS73643DBVR)
[S-1132B43-M5T1U](https://www.mouser.com/ProductDetail/628-S-1132B43-M5T1G)
U4,U5,U6,U7 | Digital Bus Switch ICs 20-Bit FET, SN74CBT16210CDGVR | TVSOP-48 | FET Level-shifter
[SN74CBT16210CDGVR](https://www.mouser.com/ProductDetail/595-SN74CBT16210CDGV)
U8 | 74LVC1G07 Single Buffer With Open-Drain Output | SOT-353, SC-70-5 | [74LVC1G07](https://www.mouser.com/ProductDetail/621-74LVC1G07SE-7)
U9 | X-tal driver 74LVC1GX04 | TSOP-6 1.65x3.05mm P0.95mm | [74LVC1GX04](https://www.mouser.com/ProductDetail/771-LVC1GX04GV125)
U10 | Bus Transceiver 74LVC245APW,118 | TSSOP-20 | [74LVC245APW-T](https://www.mouser.com/ProductDetail/771-74LVC245APW-T)
U11 | Voltage Regulator 1.8V,
MCP1702T-1802E/CB | SOT-23 | 1.8V Low Drop-Out (LDO) Voltage regulator. [MCP1702T1802E-CB](https://www.mouser.com/ProductDetail/579-MCP1702T1802E-CB)
U12 | Winslow PLCC-84 Plug | PLCC-84 Plug | Optionally homemade plug
U13 | PLCC-84_TH_pin_holes | Agnus_TH_plug_pins | Pins to use with homemade plug, 1.27mm pitch Long Pin 1x40P or 1x50P [Aliexpress](https://www.aliexpress.com/item/32894911767.html) Cut to length after soldering.
Y1 | 18pF Crystal 28.6363 MHz (NTSC) or 28.375 MHz (PAL) | 3.2 mm x 2.5 mm | [ECS-286.3-18-33-JEM-TR](https://www.mouser.com/ProductDetail/520-286.3-18-33-JEMT) (NTSC)
[ABM8-28.375MHZ-B2-T](https://www.mouser.com/ProductDetail/815-ABM8-28.375-B2-T) (PAL)
R1 | Resistor 1k Ω | 0603 | Resistor in optional Oscillator-circuit
R2 | Resistor 2.2M Ω | 0603 | Resistor in optional Oscillator-circuit
R3 | Resistor 33 Ω | 0603 | Series resistor for CLK from U9 to avoid reflections (in optional Oscillator-circuit).
R4 | Resistor 10k Ω | 0603 | Pull-up resistor for pin 41 (PAL/NTSC-selector for A500 Rev.6A/A2000/A3000-pinout) since A500 Rev.6A doesn't have pull-up on motherboard like A2000/A3000/A3000T have. Only needed for A500 Rev.6A. but doesn't hurt to populate anyway.
R5 | Resistor 4.7k Ω | 0603 | Pull-down resistor for TCK in JTAG.
RN1 | 4.7k or 10k Ω RES ARRAY 4 Resistors | 1206 | [CAY16-4701F4LF](https://www.mouser.com/ProductDetail/652-CAY16A-4701F4LF) or [CAY16-103J4LF](https://www.mouser.com/ProductDetail/652-CAY16-103J4LF)
RN2 | 4.7k (CAY16-4701F4LF) RES ARRAY 4 Resistors | 1206 | [CAY16-4701F4LF](https://www.mouser.com/ProductDetail/652-CAY16A-4701F4LF)
C1 | Capacitor Radial Polarized 100uF | 2.5mm pitch, Through-Hole | [ECE-A0JKA101I](https://www.mouser.com/ProductDetail/667-ECE-A0JKA101I)
C2-C4 | Capacitor 10uF | 1206 |
C5 | Capacitor 1uF | 0805 |
C6 | Capacitor 10uF | 0805 |
C9 | Capacitor 1uF | 0805 |
C7,C8,C10-C16 | Capacitor 0.1uF = 100nF | 0805 |
C17-C19 | Capacitor 0.01uF = 10nF | 0805 (or 0603) |
C20 | Capacitor 0.1uF = 100nF | 0603 | Decoupling cap for U8
C21-C24 | Capacitor 0.1uF = 100nF | 0603 | Decoupling caps for U4-U7
C25 | Capacitor 0.1uF = 100nF | 0603 | Optional cap for U3, NR (Noise Reduction) pin 4 on TPS73643DBVR, this pin is NC on ABLIC S-1200B43-M5T1U
C26 | Capacitor 0.01uF = 10nF | 0603 |
C27-C28 | Capacitor 0.1uF = 100nF | 0603 |
C29-C30 | Multilayer Ceramic Capacitors MLCC - 32pF | 0603 | [06031A320FAT2A ](https://www.mouser.com/ProductDetail/581-06031A320FAT2A) Caps for optional oscillator circuit
L1 | (Ferrite Bead 600ohms 100MHz .5A Monolithic) or 0 Ω resistor | 0805 | [HZ0805E601R-10](https://www.mouser.com/ProductDetail/875-HZ0805E601R-10) or 0 Ω resistor
J1 | VCC/GND Power Header Male | TH 1 x 2 Pin, 2.54mm pitch | For external power supply to allow programming of device when not plugged into the Amiga socket.
J2 | JTAG Pin Header Male | TH 2 x 5 Pin, 2.54mm pitch|
J3 | A20-A23 Pin Header Male | TH 2 x 2 Pin, 2.00mm pitch | Input Address lines for jumper-wires A20-A23
J4 | GND MountingHole_2.2mm_M2_Pad_Via | nut and bolt M2 size | for solid grounding via a ring lug connector and a thick jumper wire to Motherboard
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Select one of the crystals 28.375 MHz (PAL) or 28.6363 MHz for the optional onboard oscillator circuit. Probably you want to select PAL/NTSC opposite to what your CLK on motherboard has, this in order to be able to switch between native PAL/NTSC with only a JP-setting on the MegaChip board.
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