If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
AMI R-81 Memory Unit
|
Ads |
#2
|
|||
|
|||
AMI R-81 Memory Unit
|
#3
|
|||
|
|||
AMI R-81 Memory Unit
|
#4
|
|||
|
|||
AMI R-81 Memory Unit
On Mar 27, 2:50*am, (James McClave) wrote:
He is the one that told me mine is bad. He could repair mine, but is kinda pricey. *Was looking for one a bit cheaper in price. He wanted 3 times what I paid for the whole jukebox to repair one module, *Jim E-mail us at: It sux, but even when the special IC (which is the cause of problems with these units) was last still available, in the early 1990s it was about $120 from rowe distributors. You then have to fit it, etc. |
#5
|
|||
|
|||
AMI R-81 Memory Unit
That unit used some special/custom components that have long since
been obsolete/discontinued. When you can find them, the price is very high. |
#6
|
|||
|
|||
AMI R-81 Memory Unit
|
#7
|
|||
|
|||
AMI R-81 Memory Unit
On Mar 27, 4:41*pm, (James McClave) wrote:
If they are obsolete /discontinued , etc. Where is he finding them? *He seemed to have a good supply. I bet there is some substitute out there somewhere. Jim E-mail us at: You would need something like a PIC, AVR, CPLD to substitute, and someone has to write the software for it, this is the hard part. The chip ROWE used is not a simple logic gate, the IC has internal RAM - that's also battery backed up, bidirectional serial comms (sort of) port, (though probably more like an I2 squared design). The only good news is that the communication protocol is described in some detail in the service manual. The same applies to the selector logic, Memorec unit and credit computer. Each is a special custom IC. (for home use you can probably do without the Memorec and credit computer if they fail) but you need the memory unit and selector logic for the machine to function. Also the IC (and the whole system) is designed around negative supply voltage (-17v) which, while possible to do, is a pain in the arse to design around with modern chips. Modern microcontrollers use +5v (or in some cases 3.3v). You would have to look at a replacement board, or rider board rather than just the chip. Remember too that this system is VERY old - the earliest date stamp I have seen on these boards is 1974. The design probably dates back to the early days of this sort of technology coming into more common use, they probably paid an absolute fortune back then to have these chips and modules designed and manufactured, specially for just this purpose and nothing else. It was probably took a huge risk going to this technology, I wonder what the operators thought when they saw a totally silent black box replace a search unit, button bank, etc ? It probably scared the **** out of them, as to what to do if anything went wrong. Being straight MOS technology, they are very sensitive to static electricity also. Also note in the manual where they discuss desoldering IC's, there is nothing at all mentioned about anti-static procedures - except attatching a ground wire to the iron, or touching it to a grounded surface before using (shudder). |
#8
|
|||
|
|||
AMI R-81 Memory Unit
|
#9
|
|||
|
|||
AMI R-81 Memory Unit
On Apr 1, 2:29*pm, (James McClave) wrote:
Good info! *Thanks . I will keep looking for a memory unit thats good or will end up parting out my R-81 . Jim E-mail us at: what exactly is the problem you are having with it ? |
#10
|
|||
|
|||
AMI R-81 Memory Unit
|
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
AMI R-81 Memory Unit | James McClave | Juke Boxes | 0 | October 14th 08 06:47 AM |
AMI R-81 Memory Unit | James McClave | Juke Boxes | 0 | May 9th 08 03:36 AM |
AMI R-81 Memory Unit needed | James McClave | Juke Boxes | 1 | February 29th 08 03:41 PM |
Need CPU Memory unit gor Rockola 496? | Jim Murphy | Juke Boxes | 0 | December 17th 04 12:42 AM |
rowe R82 memory unit | Paul in Maine | Juke Boxes | 1 | September 12th 04 10:02 PM |