Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Richard Erlacher
11/21/11 21:27
Modified:
  11/21/11 21:27

Read: 423 times
Denver, Co
USA


 
#184849 - Some of us have those ... even the programmables
Responding to: Aubrey Kagan's previous message
Aubrey Kagan said:
Firstly any i8048/8049 is a ROM product and so cannot be user programmed. They can be externally enabled, bypassing the internal memory (see 8035/9 later).

Yes, that's quite true. However, they can be used with external memory just as the 805x's can. Further, the ones I have on hand are ceramic-packaged UV erasable types, i.e. 8748 and 8749. I do have an 8040, which is, in this case, a National Semiconductor part, as there were several manufacturers producing 8048-series parts under Intel license, but the 8040 is a romless (probably meaning buggered-up ROM) intended to work with larger internal read-write memory only, and external program store and XRAM.

Do you have the means to program the 8748/9? If not perhaps you should be looking at the i8035/9 which were ROMless versions and were intended to use external EPROM- something like a 2716 or 2732. As I recall it needed an octal latch also to store the lower 8 bits of the address. You do sacrifice the 8 pins of the data port as I/O and also require an i8243 I/O expander to recover the 4 port pins associated with the upper address bits (and gain another 12 I/O pins if memory serves).

Since I bought several programmers back in the day, I still have that capability. I might even be persuaded to lend one of them to someone who's anxious to use these old parts.

I probably have a few 8749s, 8039s and 8243s at home. I will check.

What about the format of the code - will you need an assembler or is it in machine code already?

There's a fellow, named Michael McCarrick, who wrote a fairly decent IDE for 8748's. It has an editor that works much like the one in turbo-C, which sort-of clones the original WordStar. It also provides a simulator and an assembler. It does, of course, assume you have a programmer, though the author would probably still be willing to sell you one of his.

-Aubrey


These are fun to play with if you used 'em in the old days. I once built a flash tester for a friend of mine who had a photoflash and camera repair business.

RE



List of 12 messages in thread
TopicAuthorDate
Sourcing historic uCs      Greg Kennedy      11/20/11 12:28      
   Vintage MCUs      Michael Karas      11/20/11 13:03      
      8041      Jan Waclawek      11/20/11 13:42      
         Unfortunately ...      Richard Erlacher      11/20/11 16:00      
            external execution in '41/'42      Jan Waclawek      11/21/11 03:15      
               I don't doubt what you said ...      Richard Erlacher      11/21/11 09:45      
   Have some old 8748, 8749 and V20 chips      Bert Van Den Berg      11/20/11 15:27      
      I've got some other old MCU and MPU chips ...      Richard Erlacher      11/20/11 16:08      
   Can you program them      Aubrey Kagan      11/21/11 13:59      
      Some of us have those ... even the programmables      Richard Erlacher      11/21/11 21:27      
   If I can find 'em ...      Richard Erlacher      11/21/11 21:30      
   seems still live      Stefan KAnev      11/22/11 08:03      

Back to Subject List