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Hi.
For years I’ve been on look-out for the upgrade ROMs for the Beomaster 4500 to upgrade it to two-way comms. I finally grabbed a NOS set that I found on eBay (not cheap but wanted to get this over with) and I uploaded the BIN files of both 1.6 and 2.2 ROMs to archive.org. Please help sharing these ROM dumps before the old EPROMs eventually fail. I hope this helps somebody else to upgrade or repair their Beomasters.
I can now get two-way IR on a BL7000. I tried MCP6500 too but that didn’t work.
Anyone know if all BM4500’s actually shipped with the two-way IR hardware or were there one-way models too?
My BM4500 now has the new ROMs, new battery, transformer wiring switched from 220V to 240V. And new adhesive on the touch-panel (although it’s still not perfect, and some previous owner had chipped the black paint on several places but I was able to mask most of it). The tuner feels somewhat low-sensitive though.
Location: Helsinki - Finland
My B&O Icons:
Thanks!
With both BIN files you can write whichever version you want (two-way comms or the BM-as-link-room-mode only in 1.6, as you pointed out in Discord).
The chip in my unit (and the replacement) was a generic 27512 EPROM, which is still readily available. Mine was M27512FI, ie. by STMicroelectronics but any manufactorer should be fine (as long it’s the same 28-pin DIP package). I couldn’t find the speed rating for either chips, but in this case I’d guess the “slowest” 200ns part should work (elsewhere, like vintage computers the speed of the ROM might be important). You’ll also need an UV-eraser (for the old EPROMs with window on top) and an EPROM programmer. I’m sure there are also newer pin-compatible variants (EEPROMs, ie. no UV-erasing needed, or write-once chips if you just want to write a chip once and not re-use it).
I find it interesting that the BM4500 was shipped with the “limiting” software (if the 2-way IR hardware was fitted). Also the release notes telling a fix for “Beosystem 4500 may intermittently block and it is necessary to remove the mains plug” sounds pretty annoying bug, and surely would’ve caused calls to dealers! (I might have actually experienced this on my unit with the old ROM once or twice, I always thought it was just an effect of a low battery but apparently not!)
Location: Helsinki - Finland
My B&O Icons:
The chip in my unit (and the replacement) was a generic 27512 EPROM, which is still readily available. Mine was M27512FI, ie. by STMicroelectronics but any manufactorer should be fine (as long it’s the same 28-pin DIP package). I couldn’t find the speed rating for either chips, but in this case I’d guess the “slowest” 200ns part should work (elsewhere, like vintage computers the speed of the ROM might be important). You’ll also need an UV-eraser (for the old EPROMs with window on top) and an EPROM programmer. I’m sure there are also newer pin-compatible variants (EEPROMs, ie. no UV-erasing needed, or write-once chips if you just want to write a chip once and not re-use it).
Thanks for the info. I have the EPROM programmer, but might have to get the UV eraser.
I find it interesting that the BM4500 was shipped with the “limiting” software (if the 2-way IR hardware was fitted). Also the release notes telling a fix for “Beosystem 4500 may intermittently block and it is necessary to remove the mains plug” sounds pretty annoying bug, and surely would’ve caused calls to dealers! (I might have actually experienced this on my unit with the old ROM once or twice, I always thought it was just an effect of a low battery but apparently not!)
Yes something about the software for this systems is like B&O was not sure what to do with it. The link room functionality is only described as being in slave mode and for future use in the user manual, so not very official. I wonder why they didn’t mentione it instead of saying for future use
Thanks!
I have an older MCUMall GQ-4X USB Programmer, but any EPROM programmer that supports these older DIP-chips should be able to read the ROMs. It takes a bit of effort to get into the CPU box and to the ROM chip, but one could of course replace the battery or caps while there… wouldn’t hurt to replace those.
The seller I bought my BM4500 two-way kit also had an BM6500 kit for sale, but the single kit was already on the expensive side with shipping so I skipped getting them both.
On a related note there is currently a BM7000 ROM for sale on german eBay (https://www.ebay.com/itm/257132321336), but although the description says 1.3, the chip label says it’s 1.1. Someone probably upgraded and put the old chip in the bag and the seller didn’t notice.
Location: Helsinki - Finland
My B&O Icons:
Added now to the archive.org item: I scanned the single-page instruction sheet on where the dealer preparing the upgrade should stick the version stickers to, and most importantly the nice two-way terminal labels (to be placed on the BM and the box) 😎
Using a Dymo labelwriter, I printed myself new ones (as the NOS stickers had completely lost adhesion).
Location: Helsinki - Finland
My B&O Icons:
I’m pretty sure I’d have seen the black two-way terminal -stickers on somewhere else but can’t remember. Then again, I might be mistaking it for the similarily styled black BEOLINK sticker that can be seen on fe. BC9000’s back (no two-way IR there but I presume it hints to the device communications over the 7-pin DIN connectors and/or the MCL2 system).
Location: Helsinki - Finland
My B&O Icons:
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