ZX21 Project ZX81 Replacement PCB

Any discussions related to the creation of new hardware or software for the ZX80 or ZX81
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fordp2002
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Re: ZX21 Project ZX81 Replacement PCB

Post by fordp2002 »

XavSnap wrote: Wed Dec 30, 2020 6:22 am Hi,

Is a Bluetooth module can be used instead of the ESP32 on ZX-Wespi project ?

For input or output transferts:
Bluetooth-Audio-Transmitter-Module-Board-4-1-Stereo-Audio-GFSK-Transceiver-Wireless-Speaker-Headphones-KCX-BT
Bluetooth-Audio-Transmitter-Module-Board-4-1-Stereo-Audio-GFSK-Transceiver-Wireless-Speaker-Headphones-KCX-BT.jpg


Can we send the AY sound to the ESP32 to retrieve the sound ?
[EDIT 1: Yes, all channels are link to the MIC socket… but if the AY sound generator is freeze, the MIC signal from the ULA will be unable to be save.]

[EDIT 2]
stereo.gif
The ZX-Wespi is based on the ESP32 chip, I would doubt anything else would work.
The sound output is independent of the MIC just sharing a connector. You can probably buy an external device to transmit the sound on Bluetooth but I am not sure many will be interested is doing this?
FordP (Simon Ellwood)
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fordp2002
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Re: ZX21 Project ZX81 Replacement PCB

Post by fordp2002 »

Happy new year all. 2021 the year of the ZX21 project!
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XavSnap
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Re: ZX21 Project ZX81 Replacement PCB

Post by XavSnap »

Happy new year Simon !
Xavier
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XavSnap
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Re: ZX21 Project ZX81 Replacement PCB

Post by XavSnap »

Suggestion:

- Add the internal 32k ram with the Wrx patch.

- Add an address rom mirroring for the offset $0004=$7F to $FF (by switch ?)

32k >> if address data=$0004 + \romcs + \Mreq = DATA>$FF

Zx ROM to init the memory room: (set the ram_top to $FFFF)

Code: Select all

0000    D3;FD            OUT ($FD),A         ; ZX81 NMI GENERATOR
0002    01;FF;7F         LD BC,$7FFF          
0005    C3;CB;03         JP $03CB            ; [RAM-CHECK]
0008    2A;16;40         LD HL,($4016)       ; GET CH-ADD
000B    22;18;40         LD ($4018),HL       ; SET X-PTR
000E    18;46            JR +71              ; [$0056:86]
0010    A7               AND A,A             ; Print-A
0011    C2;F1;07         JP NZ,$07F1         ; [PRINT-CH]
0014    C3;F5;07         JP $07F5            ; [PRINT-SP]
0017    FF               RST 38               
Note: If it's an EEprom, just poke this value in the ROM...

8-)
Xavier
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fordp2002
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Re: ZX21 Project ZX81 Replacement PCB

Post by fordp2002 »

XavSnap wrote: Sat Jan 02, 2021 12:57 am Suggestion:

- Add the internal 32k ram with the Wrx patch.

- Add an address rom mirroring for the offset $0004=$7F to $FF (by switch ?)

32k >> if address data=$0004 + \romcs + \Mreq = DATA>$FF

Zx ROM to init the memory room: (set the ram_top to $FFFF)

Code: Select all

0000    D3;FD            OUT ($FD),A         ; ZX81 NMI GENERATOR
0002    01;FF;7F         LD BC,$7FFF          
0005    C3;CB;03         JP $03CB            ; [RAM-CHECK]
0008    2A;16;40         LD HL,($4016)       ; GET CH-ADD
000B    22;18;40         LD ($4018),HL       ; SET X-PTR
000E    18;46            JR +71              ; [$0056:86]
0010    A7               AND A,A             ; Print-A
0011    C2;F1;07         JP NZ,$07F1         ; [PRINT-CH]
0014    C3;F5;07         JP $07F5            ; [PRINT-SP]
0017    FF               RST 38               
Note: If it's an EEprom, just poke this value in the ROM...

8-)
Thanks for the suggestion. There is space in the 16V8 to implement this I will look to make address pin on the RAM easier to wire to.
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XavSnap
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Re: ZX21 Project ZX81 Replacement PCB

Post by XavSnap »

this I will look to make address pin on the RAM
Good idea !
Not easy to pick up address datas on diodes and keyboard socket…
A11,A12,A13,A15 & /M1 Pins near the bottom of the ram socket.
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fordp2002
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Re: ZX21 Project ZX81 Replacement PCB

Post by fordp2002 »

Easier on the ZX21 as pretty much all the signals are on one of three debug connectors.
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Re: ZX21 Project ZX81 Replacement PCB

Post by XavSnap »

For example, move the optionals socket to the bottom case:
dktronic kb to the bottom to avoid to pass the ribbon wiring on the top, and keep the old kb…
dk.jpg
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Re: ZX21 Project ZX81 Replacement PCB

Post by blittled »

I didn't notice the DB9 connector until I looked at the recent picture. Is that a standard RS232 port?
2X Timex Sinclair 1000, ZX81, ZX80Core, 5X 16K Ram Pack, ZXBlast, ZX P file to Ear Input Signal Converter, Elf II
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Re: ZX21 Project ZX81 Replacement PCB

Post by 1024MAK »

blittled wrote: Fri Jan 08, 2021 1:58 pm I didn't notice the DB9 connector until I looked at the recent picture. Is that a standard RS232 port?
It’s a joystick port.

Mark
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