/GottaGoFaZt3r

Zorro III Fast RAM for Amiga 3000/4000

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GottaGoFaZt3r Fast RAM

256MB Autoconfig Fast RAM for the Amiga 3000/4000

PCB

Table of contents

  1. Status
  2. Features
  3. Ordering PCBs
  4. Bill of materials
  5. Troubleshooting
  6. Special Thanks and Shoutouts
  7. License

Status

Tested and working in the following configurations:

  • Amiga 3000
  • Amiga 4000 with A3640

Features

128MB or 256MB Z3 Fast RAM
Brand new 32Mx16 SDRAM chips are quite expensive so the board can also be fitted with 16Mx16 chips for a much lower build cost

Ordering PCBs

I recommend ordering from JLCPCB as this board was designed within their 4-layer specifications
Recommended options when ordering:

  • Thickness: 1.6mm
  • Surface Finish: ENIG-RoHS
  • Gold Fingers: Yes
  • 45°finger chamfered: Yes

Layer sequence:

Layer File
L1 GottaGoFaSDZ3-F_Cu.gbr
L2 GottaGoFaSDZ3-In1_Cu.gbr
L3 GottaGoFaSDZ3-In2_Cu.gbr
L4 GottaGoFaSDZ3-B_Cu.gbr

Bill of materials

Component Location QTY Link Notes
0.1uF Ceramic Capacitor, 0603 C4-15,C17-44 40 Mouser
DigiKey
10uF Ceramic Capacitor, 1206 C2-3,C16 3 Mouser
DigiKey
33 Ohm Resistor, 0603 R1 1 Mouser
DigiKey
33 Ohm Resistor network, Convex 1206 (3.2x1.6mm) RN1-8 8 Mouser
DigiKey
10K Resistor, 0603 R2 1 Mouser
DigiKey
LM1117-3.3 SOT-223 U1 1 Mouser
Digikey
74LVC245N TSSOP U2-5 4 Mouser
DigiKey		 Can be substituted with SN74LVTH245 or SN74LVCR2245
AS4C32M16SC 32Mx16 SDRAM, TSSOP-54 U7-10 4 Mouser
DigiKey		 Cheaper option is to use A3V56S40GTP 16Mx16 for a 128MB configuration at a drastically lower price, or scavenge some 32Mx16 SDRAM from old SODIMMs*
Xilinx XC95144XL-10TQG100C 10ns 144 Macrocell CPLD U6 1 Mouser
Digkey
Clock Oscillator, HCMOS, 7x5mm, 3.3V, ~66MHz X1 1 Mouser
DigiKey		 Anything close to 66MHz should work
Tested at 66.6666MHz

* I cannot provide technical support for RAM chips other than those explicitly listed in the BOM, others may work but you're on your own

Troubleshooting

Problem: The board is detected but there is less memory detected than there should be. or you see a message stating that the board is "Defective"
Resolution:

  1. Check all soldering looking for bad connections and shorts around the RAM and CPLD
  2. Test the RAM using ATK
    Look for the relevant region under "List and test regions" and test it
    Consult the memory layout to determine which IC is responsible for any stuck bits you might see

Memory Layout

The memory is laid out in a way that causes it to wrap around above 128MB when only 128MB of ram is fitted to the card allowing either 128/256MB configuration with the same CPLD firmware.
Kickstart will notice this wrap and add only 128MB to the free pool in this instance.

Address D0-15 D16-31
40000000-43FFFFFF U7 U9
44000000-47FFFFFF U8 U10
48000000-4BFFFFFF U7 U9
4C000000-4FFFFFFF U8 U10

Special Thanks and Shoutouts

  • Niklas Ekström for helping to clean up my messy code
  • GadgetUK164 for being a guinea pig beta testing many of my boards
  • SparxUK also for being a helpful beta tester of many of my boards
  • CDH and Stefan Reinauer for helping me to get my A3000 going
  • Rob "peepo" Taylor whose A500++ got me started on my journey of tinkering with Amigas
  • jbilander who came up with the cool name :)
  • RetroFletch
  • SukkoPera

License

CC BY-SA 4.0

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

CC BY-SA 4.0