Ideal EEPROM for 6502

[Nogard]

Dear community,
I am newbie student in this thread. However, I have been searching for some projects with 6502 and I have noticed, that almost everyone uses AT28C256 EEPROM. Can I ask why, what is the reason? Programmers for those 28 series EEPROMs are quite expensive. Can I use 24, 25 or 26 series of the EEPROM for my Rockwell R6502AP? I am asking, because I really do not want to spend like 50 USD on the EEPROM programmer. I have CH341A usb programmer from China for somewhere around 3 USD. It could be also much easier to include the CH341A in 6502 PC.
Thank you for all the answers.
Nogard

[cbmeeks]

I started a recent thread about the same thing.

viewtopic.php?f=4&t=5825

However, I don't think the programmers are as expensive as they used to be. eBay is full of them.
And, there are examples of people using Arduino's to program them manually.

[Martin A]

To run code from, you need an 8 bit parallel memory device, which basically means 27, 28, 29 or 39 series EPROM, EEPROM or FLASH. You also need to make sure you pick a 5 volt device.

24 (I2C), 25 (SPI) and 26 (SQI) are all serial format devices. With suitable interfacing they can be used for data storage if the voltage levels are taken into account, but not for running code.

[BigEd]

(Welcome, Nogard!)

[Nogard]

Thank you for all the answers. So my CH341A USB EEPROM programmer is useless for this project. Alright, so I need new one. Any recommendations?

[cjs]

Nogard wrote:

Thank you for all the answers. So my CH341A USB EEPROM programmer is useless for this project. Alright, so I need new one. Any recommendations?

Just homebrewing a programmer with an Arduino board seems to be a very popular option. Despite being more powerful than a typical programmer, they seem to be cheaper and of course you can program a huge variety of EPROMs via existing software or even by writing your own.

I'd consider the only tricky part to be dealing with 12 V write voltages and the like, if your EPROM needs that. (I think many of the modern ones don't.) But also I'm much stronger on the software side than the hardware side.

I'm kinda surprised this isn't the first option most people consider these days. Am I missing something here?

[Nogard]

Hello jcs,
No, you are not missing anything. Thank you for the opinion.
Before I will start ordering and building the Arduino EEPROM Programmer, I will ask a question.

Any of those EEPROMs really can not be used to run code for 6502 from?

Note: ESMT SST Series 25 can be read only, can not be written due to CH341A characteristic. 25\26Series devices support list: AMIC
A25L512 A25L05P A25L10P A25L010 A25L020
A25L20P A25L40P A25L040 A25L080 A25L80P
A25L016 A25L16P A25L032 ATMEL
AT25F512 AT25F512B AT25F512A AT25FS010 AT25F1024
AT25F1024A AT25F2048 AT25DF021 AT25F4096 AT25FS040
AT25DF041A AT26F004 AT26DF081A AT25DF161 AT26DF161
AT26DF161A AT25DF321A AT26DF321 AT25DF321 AT25DF641 COMMON
25X005 25X05 25X10 25X20 25X40
25X80 25X16 25X32 25X64 25X128
25X256 25X512 25X1024 25X2048 EON
EN25F05 EN25P05 EN25LF05 EN25F10 EN25LF10
EN25D10 EN25P10 EN25F20 EN25D20 EN25LF20
EN25F40 EN25D40 EN25LF40 EN25Q80 EN25D80
EN25F80 EN25P80 EN25T80 EN25B16T EN25T16
EN25B16 EN25D16 EN25F16 EN25Q16 EN25P32
EN25Q32 EN25F32 EN25B32 EN25B32T EN25Q64
EN25B64 EN25F64 EN25B64T EN25F128 EN25Q128 ES
ES25P10 ES25P20 ES25M40A ES25M40 ES25P40
ES25M80 ES25M80A ES25P80 ES25M16 ES25M16A
ES25P16 ES25P32 ESMT
F25L04UA F25L004A F25L08PA F25L008A F25L016A
F25L16PA F25L32QA F25L32PA GIGADEVICE
GD25Q512 GD25Q10 GD25Q20 GD25F40 GD25D40
GD25Q80 GD25D80 GD25T80 GD25F80 GD25Q16
GD25Q32 GD25Q64 GD25Q128 KH
KH25L8036D MXIC
MX25V512 MX25L512 MX25L1005 MX25L2005 MX25L8035
MX25L4005A MX25V4035 MX25V4005 MX25V8005 MX25L8005
MX25L1635D MX25L1605D MX25L1608D MX25L3235D MX25L3208D
MX25L3237D MX25L3225D MX25L3205D MX25L3206E MX25L6405D
MX25L6455E MX25L6408D MX25L6406E MX25L6445E MX25L12805D
MX25L12845E NEXFLASH
NX25P10 NX25P20 NX25P40 NX25P80 NX25P16
NX25P32 NSHINE
MS25X05 MS25X10 NS25X20 NS25X40 MS25X80
MS25X16 MS25X32 MS25X64 MS25X128 PMC
PM25LV512A PM25LV010A PM25LV020 PM25LV040 PM25LV080B
PM25LV016B SAIFUN
SA25F005 SA25F010 SA25F020 SA25F040 SA25F080
SA25F160 SA25F320 SPANSION
S25FL004A S25FL040A S25FL008A S25FL160 S25FL016A
S25FL032A S25FL064A S25FL128P S25FL129P S25FL128A SST
SST25VF512A SST25VF512 SST25VF010 SST25VF010A SST25VF020A
SST25VF020 SST25VF040B SST25VF040A SST25VF040 SST25VF080B
SST25VF016B SST25VF032B SST25VF064C ST
M25P05A M25PE10 M25P10A M25P20 M25PE20
M25PE40 M25P40 M25PE80 M25P80 M25PX80
M25PX16 M25P16 M25PE16 M25P32 M25PE32
M25PX32 M25PX64 M25P64 M25PE64 M25P128 WINBOND
W25X10 W25X10L W25P10 W25X10AL W25X10A
W25P20 W25X20AL W25X20A W25X20 W25X20L
W25X40A W25P40 W25Q40BV W25X40L W25X40
W25X40AL W25Q80BV W25Q80V W25X80 W25P80
W25X80A W25X80L W25X80AL W25P16 W25Q16BV
W25Q16V W25X16 W25Q32BV W25Q32V W25X32
W25P32 W25Q64BV W25X64 W25Q128BV


=====24Series devices support list===== ATMEL
AT24C01B AT24C01 AT24C01A AT24C02 AT24C02A
AT24C02B AT24C04B AT24C04 AT24C04A AT24C08A
AT24C08B AT24C08 AT24C16 AT24C16A AT24C16B
AT24C32B AT24C32A AT24C32 AT24C64 AT24C64A
AT24C64B AT24C128 AT24C128A AT24C128B AT24C256B
AT24C256 AT24C256A AT24C512B AT24C512A AT24C512
AT24C1024 AT24C1024A AT24C1024B CATALYST
CAT24C01 CAT24WC01 CAT24WC02 CAT24C02 CAT24C04
CAT24WC04 CAT24WC08 CAT24C08 CAT24WC16 CAT24C16
CAT24WC32 CAT24C32 CAT24WC64 CAT24C64 CAT24WC128
CAT24C128 CAT24WC256 CAT24C256 CAT24C512 CAT24WC512
CAT24C1024 CAT24WC1024 COMMON
24C01 3V 24C01 5V 24C02 3V 24C02 5V 24C04 5V
24C04 3V 24C08 3V 24C08 5V 24C16 5V 24C16 3V
24C32 5V 24C32 3V 24C64 5V 24C64 3V 24C128 5V
24C128 3V 24C256 5V 24C256 3V 24C512 5V 24C512 3V
24C1024 3V 24C1024 5V 24C2048 5V 24C2048 3V 24C4096 5V
24C4096 3V FAIRCHILD
FM24C01L FM24C02L FM24C03L FM24C04L FM24C05L
FM24C08L FM24C09L FM24C17L FM24C16L FM24C32L
FM24C64L FM24C128L FM24C256L FM24C512L FM HOLTEK
HT24C01 HT24LC01 HT24C02 HT24LC02 HT24C04
HT24LC04 HT24C08 HT24LC08 HT24C16 HT24LC16
HT24LC32 HT24C32 HT24LC64 HT24C64 HT24C128
HT24LC128 HT24C256 HT24LC256 HT24LC512 HT24C512

[Martin A]

The 6502 family (and pretty much everything of that era) works with parallel memory.

I happened to have a 24 series serial eprom as used by a Parallax Propeller and large capacity 39 series flash, close to hand. As you can see, they are totally different.

The parallel device reads the address from the CPU in one go, and outputs all of the data byte at once over 8 pins.

The serial device will have the address sent one bit at a time, and will reply with the data one bit at a time.

So no, you can't use anything on that list to run code from, as they all seem to be 24 or 25 series types.

Totally different beasts

[Nogard]

Alright, I just wanted to ensure myself. Thank you so much for it.

The last question is: Can I use any of these solutions?

#1 Solution
https://www.ebay.com/itm/AVR-ISP-Shield ... 0752.m1982

#2 Solution
https://forum.arduino.cc/index.php?topic=163682.0

#3 Solution
https://github.com/crmaykish/AT28C-EEPR ... er-Arduino

#4 Solution
http://blog.tynemouthsoftware.co.uk/201 ... ammer.html

[thedrip]

1 -- no.
2,3 and 4 -- yes, for 28 series devices.

[Nogard]

Alright, I really want to thank you all, who have joined this thread. Thank you for your patience with me.

[6502user]

Dear community:

I'm sorry, I know this topic is so old. I need to know if a can connect the 28C64/128/256 eeproms to NMOS R6502 (not CMOS 6502) without 74HCT244/245 between the NMOS cpu and CMOS eeeprom.

I would be very grateful if you could clarify this question for me. Kind regards.

[BigDumbDinosaur]

6502user wrote:

I need to know if a can connect the 28C64/128/256 eeproms to NMOS R6502 (not CMOS 6502) without 74HCT244/245 between the NMOS cpu and CMOS eeeprom.

Yep!