Found an 8052-AH-BASIC

[syzygy]

I have been looking for one for a while and ordered one of these. Been playing around with AT89S52 (a modernized compatible) and burning the BASIC into onboard memory. But, I could not resist getting the genuine article - well, I am hoping it is the genuine article.

I always wanted to build a little system with the 8052-AH-BASIC. This had an onboard BASIC burned in so one did not have to learn *real* programming as with the others in the MCS-51 series or the predecessors. Consequently, there were a lot of projects published at the time using the chip. I used to read about these but never had the time or $$ to go further.

Did anyone here have experience with the 8052-AH-BASIC?

I do hope it is genuine and not relabeled or some other such nonsense. I thought it was worth the risk as I have not seen one for sale in over a year.

 

[syzygy]

*sigh*

My thinking now is...likely one like this or this or this but I should wait to receive it and check it out, since I don't know for sure.

Oh well, likely, $21.91 --> flushed. I wonder what they used?

 

[wrm]

I made a PCB using smARTWORK back in the day, basically the reference design from the BASIC-52 manual, with more sockets.

When you run BASIC you can save your programs to EPROM, so it's 8052-AH-BASIC + 32K RAM + 32K EPROM.

Other configs were 8031/8032 with external EPROM, that would also run BASIC but won't save the code to EPROM.

Or of course I could write code in assembler or PL/M or C...

Still have all that stuff kicking around. Documented on my website as well.

 

[daver2]

I am not sure why you think you have flushed money down the drain?

If it is not the genuine article upon arrival, ask for your money back.

It is claimed to be the P8052AH-BASIC - so it should be...

Dave

 

[syzygy]

I went to your page and checked out your board – very nice.

As I mentioned, I did want to build something with the 8052-AH-BASIC since back in the day. Recently, I started to breadboard the AT89S52, but had to to stop, box, and get back to finishing other projects that I have started (see here).

I like your design. I want to just try something minimal, but still usable. Jan Axelson’s Microcontroller Idea Book features the 8052-BASIC and has a ton of information in it, including designs.

I think I am going to, eventually, breadboard this guy's simple 3 chip design. He still has a couple of GPIO available and should give me plenty to play with. One other feature I would like to add some video out using Geoff's terminal - but not the full board, just the composite video out seen here. I have programmed that PIC before and it should be manageable for me. So, I would program the chip and save the BASIC program using using a modern computer as a terminal, but the final project would have video output.

 

[syzygy]

I am not sure why you think you have flushed money down the drain?

If it is not the genuine article upon arrival, ask for your money back.

It is claimed to be the P8052AH-BASIC - so it should be...

Dave

The short answer is that I should know better.

I don't have it yet, so I don't know what I will get. The pic in the advert looks like this one. Note the (2021) in the description of that advert. I don't think Intel was making an 8052-AH-BASIC in 2021. I think it is a remake and not by Intel - to me, that means it is not the genuine chip. Is that grounds to ask for money back? The seller, does not offer returns, and it was ordered from another country. Is what was sent accurately described? How much is my time worth? Like I said, I should have known better - maybe I will be pleasantly surprised. I bought two genuine AT89S52 from Microchip for less, so I should have known better

 

[daver2]

It also appears to be described as a 6845 controller as well...

No, Intel were not making these in 2021.

If it arrives and is not what is pictured - I would just ask eBay for my money back.

It doesn't matter if the seller states "no returns" if they shipped the item that they were not advertising for sale...

Dave

 

[syzygy]

It also appears to be described as a 6845 controller as well...

No, Intel were not making these in 2021.

If it arrives and is not what is pictured - I would just ask eBay for my money back.

It doesn't matter if the seller states "no returns" if they shipped the item that they were not advertising for sale...

Dave

Yeah, I see your point.

To be accurate, the pic in the advert from which I ordered looks like pics of the genuine chip, based on the position of the M and C after Intel. The one from the advert marked (2021) has the M and C before Intel. If I can determine that it is genuine - hooray and a really good deal. If I can figure out that it is not genuine, boo and boohoo.

 

[syzygy]

To follow up....I did receive the chip a week or so ago...this is it..



I do not know if this was made by Intel. It could have been and the 9035 could be a date code. I just don't know and I have searched around on the subject and found nothing determinant.

Not sure when I will get this project going and there may be information within the chip that will shed some light on the subject.

 

[gslick]

For what it's worth, here is a P8052AH-BASIC chip I purchased on eBay back in 2017 which also has a 9035 code on the bottom.

The printing on the top of the one I have looks slightly different than on the one you have. The character spacing looks closer to fixed width on the one I have and spread out slightly wider compared to the one you have. No idea if that really means anything.

 

[syzygy]

Appreciate you posting it and I agree on the differences. Also agree that I don't know what that means.

 

[syzygy]

Got around to doing some more more on this 'project'

Bread boarded the simple 3 chip system straight from the MCS Basic-52 Operating and reference manual.


Connected up Tera Term and....



Then I substituted an AT89S52 which I had programmed with 8052 AH-Basic V1.3


Sweet!

I better go lie down on the couch for a while, all this stuff working is fatiguing

 

[syzygy]

Continuing on with this "just for S&G" project, I got a LILYGO ESP32 TTGO board to assist in making a dedicated terminal. The FABGL library (Fabrizio Di Vittorio) has a terminal software example with several terminal choices. I am impressed. It loaded easily - well, it took a while to figure out that my legacy Arduino IDE (1.819) choked on Espresif's latest lib and once I downgraded to version 2.017, it compiled with no complaints. I have browsed some of the code and it seems feasible for me to customize it a bit if need be. I am just testing out the ANSII and VT52 selections.



I had an old beat up MS PS2 mouse and that worked with the board but was not very responsive even after a brisk cleaning. I decided to splurge on an $8 mouse which works much better. Truth is, I don't think I will be using the mouse with the terminal, but I don't mind having a working PS2 mouse on hand.

I have an old and full-size PS2 keyboard purchased for a few bucks at a thrift shop and it works ok with the board. The "vision", however, was to use a very small footprint keyboard and this one fit the bill nicely....and it works fine with a USB to PS2 adapter.

As for the video, the board outputs VGA. I previously wrote about this 14" TV that I purchased a while ago. I really like this TV and it has VGA input and it works nicely with the terminal software. I didn't bother loading Space Invaders, so I can't say much about graphic capabilities.

Even though I have plenty of odds and ends speakers and amplifier components around, I want a nice little speaker set that would fit snugly on the monitor base. This one works fine for $9.

Since the ESP32 is 3.3V and the 8052 5.0V, I used a level shifter. I know I could have used resistors, but I had plenty of these generic TXS0108E boards and who knows if I might need to mess around with RTS and CTS and I have unused gates.



The minimal 8052AH-Basic on the breadboard will need to be expanded and I am going through the literature to settle on how much I want to do to finish the implementation.

So far, so good.

 

[Twospruces]

I went to your page and checked out your board – very nice.

As I mentioned, I did want to build something with the 8052-AH-BASIC since back in the day. Recently, I started to breadboard the AT89S52, but had to to stop, box, and get back to finishing other projects that I have started (see here).

I like your design. I want to just try something minimal, but still usable. Jan Axelson’s Microcontroller Idea Book features the 8052-BASIC and has a ton of information in it, including designs.

I think I am going to, eventually, breadboard this guy's simple 3 chip design. He still has a couple of GPIO available and should give me plenty to play with. One other feature I would like to add some video out using Geoff's terminal - but not the full board, just the composite video out seen here. I have programmed that PIC before and it should be manageable for me. So, I would program the chip and save the BASIC program using using a modern computer as a terminal, but the final project would have video output.

Hi, have you made any progress on this? I'm interested in this idea also. I wonder if an 11MHz 80C31 is fast enough?

 

[syzygy]

I confess that I have not [yet] done much else on this project [and many others]. Still, I do want to put together a small board and do not have too much more to do....just knee deep in the TRS80 MI projects.

Have you seen this book (now available for free and with program listings and corrections. I am planning on lifting an enhanced version of the minimal system that I already bread boarded based on one of her schematics and what I have on hand. Probably add a couple of relays. I was also planning on using this repurposed PS and enclosure for the project.

wonder if an 11MHz 80C31 is fast enough?

For what?

 

[Twospruces]

I confess that I have not [yet] done much else on this project [and many others]. Still, I do want to put together a small board and do not have too much more to do....just knee deep in the TRS80 MI projects.

Have you seen this book (now available for free and with program listings and corrections. I am planning on lifting an enhanced version of the minimal system that I already bread boarded based on one of her schematics and what I have on hand. Probably add a couple of relays. I was also planning on using this repurposed PS and enclosure for the project.



For what?

Fast enough to support the terminal application.

 

[syzygy]

Fast enough to support the terminal application.

Ahh, ok. Well, with my minimal testing, it was ok....of course the LILYGO ESP32 TTGO was doing all the work - as I recall the 8051 was at 9600 and an 11.0592. For just messing around writing simple BASIC code, it was fine for me. Again, to the extent that I used it. I am pretty impressed by the LILLYGO because, of course, it is doing the video and the keyboard. Hardly retro, but functionally it gets the job done in the most economical fashion that I found.

 

[gertk]

Just found my 8052AH Basic back again and put it on a small protoboard together with a 8k SRAM, 8k EEPROM and the usual latch and decoding TTL chips.
Crystal is tucked away under the CPU as is the reset capacitor. Connection to the PC (and also delivering power) is through a FTDI USB to TTL serial board. It runs fine. Current draw is about 110 mA

It is quite amazing what they put in that internal 8 kByte ROM: a comprehensive Basic with floating point, arrays, (e)eprom programming, timer functions etc.
Not a 'Tiny Basic'

 

[gertk]

I have been fiddling with my 8052AH board and modified it to incorporate 32kB SRAM (only data space from $0000-$7FFF) and a 32kB EEPROM (mapped in code space, 4 banks of 8 kB at $2000/$4000/$8000/$A000) but this EEPROM does not have a 'ready' line.

When going through the source of the Version 1.1 CPU I noticed a routine called PG7 which handles single byte programming and returns without checking.

I tried to call it from a small assembler routine but realized that if I put the routine in the EEPROM it 'saws of the branch I am sitting on' during programming as the EEPROM is not accessible while it is writing internally (3 to 10 ms).

So I squeezed in another 8 kB SRAM underneath the EEPROM which is mapped in program and data space at $E000-$FFFF. Alas the system still crashes when I try to call the internal routine PG7. I filled in the correct register values for address and data but after doing a CALL to the subroutine from Basic it hangs or returns with an error after which Basic locks up.

Any ideas?

 

[wrm]

Understand that to program the EPROM the code in the internal ROM switches the 8052 from external bus mode to I/O mode, then runs from internal ROM (using the internal RAM for storage) and programs the EPROM.