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Thread

Using keyboard parts for rack mount version

2014-08-05 by hotnixon7@...

Hi folks,

I just purchased an emax se keyboard and already have a rack mount version but it's missing the floppy drive and power supply. Should I swap parts from the keyboard and fix up the rack? 

Thanks,

Brian

Sent from my iPhone

Re: [emax] Using keyboard parts for rack mount version

2014-08-05 by Ted Summers

Brian-

parts are interchangeable.

Or you can get replacements / upgrades (slim floppy / flash drive) to have two functioning units.

See examples / more here:

djtbs1.wordpress.com

Some replacement parts available from EPR Electronics (Florida, US) - just google them.

Regards,

Ted Summers

Co-Moderator

Yahoo! Emax Users Group

On Aug 5, 2014, at 4:45 AM, hotnixon7@yahoo.com [emax] wrote:

Hi folks,

I just purchased an emax se keyboard and already have a rack mount version but it's missing the floppy drive and power supply. Should I swap parts from the keyboard and fix up the rack?

Thanks,

Brian

Sent from my iPhone

Re: [emax] Using keyboard parts for rack mount version

2014-08-05 by JAMIE logan

all the parts are the same the rack just does not have the keyboard or the keyboard ribbon cable or the extra lead for the wheels it only has the floppy power connector

but some keyboard digital logic boards only have a small logic to digital board cable and they are not split like on the rack version

the reason they are split on the rack version is the outer cables of the ribbon are by a power regulator and they can pick up interference in that in a

bulletin for techs was the splitting of the wires so that they could be bunched but i fit a ferrite bead on mine as it stops all interference

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On 5 August 2014 15:04, Ted Summers djtbs1@... [emax] <emax@yahoogroups.com> wrote:

Brian-
parts are interchangeable.

Or you can get replacements / upgrades (slim floppy / flash drive) to have two functioning units.

See examples / more here:

djtbs1.wordpress.com

Some replacement parts available from EPR Electronics (Florida, US) - just google them.

Regards,
Ted Summers
Co-Moderator
Yahoo! Emax Users Group

On Aug 5, 2014, at 4:45 AM, hotnixon7@... [emax] wrote:

Hi folks,

I just purchased an emax se keyboard and already have a rack mount version but it's missing the floppy drive and power supply. Should I swap parts from the keyboard and fix up the rack?

Thanks,

Brian

Sent from my iPhone

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by tonykirby100@...

Hi Ted, I'm new to the group. So please excuse me finding my way through things. I am looking to upgrade the EEPROM on my Emax2 to take it up to 8mb. I think I read on the forum that you could possibly supply me with one of these 8pin IC's or at least point me in the right direction. Look forward to your reply. Kind regards, Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by JAMIE logan

for that to work you need the 4mb expansion board as with out that you cant burn the pal chips and you also need the unscrambled megs code which ids $60 from epr as they are the only persons with the equipment to use the code number from your device to get the code needed to unscramble them

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On 7 August 2014 18:20, tonykirby100@... [emax] <emax@yahoogroups.com> wrote:

Hi Ted, I'm new to the group. So please excuse me finding my way through things. I am looking to upgrade the EEPROM on my Emax2 to take it up to 8mb. I think I read on the forum that you could possibly supply me with one of these 8pin IC's or at least point me in the right direction. Look forward to your reply. Kind regards, Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by tonykirby100@...

Hi Jamie,

I have the 4mb expansion board. I just think if changing the 8mb eeprom works it would be more sustainable for the future than one individual person/company charging $60 a time to decode the numbers. Just an idea?

Regards

Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by JAMIE logan

yes i agree but who is going to write the eprom with the code to stop the scrambled megs

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On 7 August 2014 19:12, tonykirby100@... [emax] <emax@yahoogroups.com> wrote:

Hi Jamie,

I have the 4mb expansion board. I just think if changing the 8mb eeprom works it would be more sustainable for the future than one individual person/company charging $60 a time to decode the numbers. Just an idea?

Regards

Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by tonykirby100@...

Hi Jamie,

I may have got this wrong and if someone knows this to be the case then please advise. The way I see it if the small eeprom is changed for the one that contains the details for 8MB, then the system should work without seeing a problem. I understand that Ted, one of the moderators of this group has already managed to place this code onto one of these small IC's and the code is already on this site as a file. Look forward to any comments. Regards, Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by JAMIE logan

with the extra ram you got a floppy disk that added the code for the extra ram banks

but the emax 2 can still get scrambled megs and you need to recode them as the disks are a 1 time use and i have never seen an image of one the only other way is to input the code to unscramble them

i know i have been through this with a customer who brought the code and used it and it scrambled again and they wanted to charged him the full 8mb unscramble code evewn though he paid for it a few weeks before

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On 7 August 2014 19:33, tonykirby100@... [emax] <emax@...m> wrote:

Hi Jamie,

I may have got this wrong and if someone knows this to be the case then please advise. The way I see it if the small eeprom is changed for the one that contains the details for 8MB, then the system should work without seeing a problem. I understand that Ted, one of the moderators of this group has already managed to place this code onto one of these small IC's and the code is already on this site as a file. Look forward to any comments. Regards, Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by tonykirby100@...

Hi Jamie, Yes I have heard what you say before about the install disc. It was a way of ensuring you bought the upgrade from EMU I suppose. However, there is always more than one way to do things and as these chips fail it would be good to know if it works to just transplant an 8MB eeprom. I think it will, that is possibly why they soldered the eeprom to the board? To make it harder to change?

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by JAMIE logan

you can transplant a 8mb version and can upgrade a 4mb to a 8mb but with out the disk you have to add the code from epr to access it

the disk adds the code to the main board and not the memory expansion

the scrambled megs code allows you to make the mainboard know that the 8mb or 4mb is installed so that it will use the logic to switch the ram

with out it the machine is only seen as a 2mb machine

you need the 8mb eprom on the memory expansion and the pal chip so that it can do the logic ras/cas instructions

with out them on the expansion it will be only a 4mb board

but the 1 time disk set the code on the mainboard so that you do not have to do it manually like you have to with the scrambled megs code

and why i said about the mainboard eprom who was going to write the code to it so that you never need to add the scramble megs code

and there was only ever an memory expansion by emu

for the cost of manufacturing a new one and programming chips its actually cheaper to buy a 8mb emax2

but if there was enough interest to start up a kick starter for a new expansion board i can certainly get one made

but there needs to be enough pledges to even make it a non profit expansion

we already make a few upgrades for synths and replacement asic chips for ones no longer available and working on others

and my dual scsi floppy combo drive is nearly at the finishing stages late sept/early oct just waiting on metal work to be manufactured and powder coated

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On 7 August 2014 20:33, tonykirby100@... [emax] <emax@yahoogroups.com> wrote:

Hi Jamie, Yes I have heard what you say before about the install disc. It was a way of ensuring you bought the upgrade from EMU I suppose. However, there is always more than one way to do things and as these chips fail it would be good to know if it works to just transplant an 8MB eeprom. I think it will, that is possibly why they soldered the eeprom to the board? To make it harder to change?

Re: [emax] Using keyboard parts for rack mount version

2014-08-07 by tonykirby100@...

Hi Jamie,

I'm glad to see the work your doing and that's all great stuff, especially the SCSI gear. To clarify exactly what I want to do. I have the original EMU expansion board complete with 2MB. My emax is 2MB so clearly if I installed that board and did the scrambled megs via EPR I would get 4MB. Also I have all the additional ram required to make the unit 8MB by installing the extra 32 chips on the expansion board. After reading all the available upgrade literature from EMU and further checking. It would appear that once you get beyond 4MB you don't need to add or remove any Pals or wire links from the expansion board. If I understand correctly all the non volatile information such as memory size and boot order is stored on the 8 pin eeprom on the main board. If this chip was desoldered, socketed and replaced with the correct 8MB version. I can't see why is should not just work. The floppy would have just run some software that programmed the eeprom with the new memory size. Clearly that's why they made it self corrupt to save people just doing it as and when they fancy. My aim is to make this work and keep a spare eeprom to swap out thus saving me having to both rely on and pay a third party. If anyone can help with this then please contact me.

Regards

Tony

Re: [emax] Using keyboard parts for rack mount version

2014-08-08 by Ted Summers

Tony-

Someone else on the group (Dave, I think) had said he got it to work by rearranging PALs and placing the EEPROM with the file.

But I never got this to work. Nor do I have PALs for this upgrade or the binaries.

My understanding is if you have the correct PALs and the expansion board populated with memory, you can call EPR to get the code as Jammie has explained.

I ended up buying 2 Emax IIs to get one that had Stereo and 8MB.

-Ted

On Aug 7, 2014, at 1:40 PM, JAMIE logan jammie.emma@blueyonder.co.uk [emax] wrote:

you can transplant a 8mb version and can upgrade a 4mb to a 8mb but with out the disk you have to add the code from epr to access it

the disk adds the code to the main board and not the memory expansion

the scrambled megs code allows you to make the mainboard know that the 8mb or 4mb is installed so that it will use the logic to switch the ram

with out it the machine is only seen as a 2mb machine

you need the 8mb eprom on the memory expansion and the pal chip so that it can do the logic ras/cas instructions

with out them on the expansion it will be only a 4mb board

but the 1 time disk set the code on the mainboard so that you do not have to do it manually like you have to with the scrambled megs code

and why i said about the mainboard eprom who was going to write the code to it so that you never need to add the scramble megs code

and there was only ever an memory expansion by emu

for the cost of manufacturing a new one and programming chips its actually cheaper to buy a 8mb emax2

but if there was enough interest to start up a kick starter for a new expansion board i can certainly get one made

but there needs to be enough pledges to even make it a non profit expansion

we already make a few upgrades for synths and replacement asic chips for ones no longer available and working on others

and my dual scsi floppy combo drive is nearly at the finishing stages late sept/early oct just waiting on metal work to be manufactured and powder coated

On 7 August 2014 20:33, tonykirby100@... [emax] <emax@yahoogroups.com> wrote:

Hi Jamie, Yes I have heard what you say before about the install disc. It was a way of ensuring you bought the upgrade from EMU I suppose. However, there is always more than one way to do things and as these chips fail it would be good to know if it works to just transplant an 8MB eeprom. I think it will, that is possibly why they soldered the eeprom to the board? To make it harder to change?