Astro Spectra Control Head Question (A9 to W9)

[BIGLDH]

Hey gang!

I apologize for posting a question that I've ssen previously posted, but the thread is over two years old and I didn't see anything that truly answered my question, so please bear with me.

I have ann Astro spectra 110W unit and I have a W9 REAR control head. Is there ANY way to convert this to a FRONT control head?

Also, I have a TON of Spectra A9 heads and have read they can be done by replacing the EPROM (which I have never done, but feel comfortable to attempt it). Where / who has these EPROMs and is there a thread that details the procedure or a resource you could guide me to?

Thanks in advance for your time and help! I look forward to hearing from you!

Dale

[Will]

Just install the actuator for the on off switch and connect as the front head. You may have to change a couple of button functions in CPS.

[eleet]

To convert an A9 to ASTRO you must replace the PROM. It is a 27c256 in a PLCC socket. Due to the way it is made most chip pullers will not work. You should buy a new chip puller, and take apart your old puller at the hinge/pivot, then you will be able to use the two halves of the puller without damaging the socket.

I have some spares so PM me if you need.

[jmr061]

Actually the rear head and front heads have different programming in the soldered on PROM on the board. This has been documented by at least one person I know. If you use a rear head on the front you may end up getting occassional mishaps.

Jason

[eleet]

Actually the rear head and front heads have different programming in the soldered on PROM on the board. This has been documented by at least one person I know.

What heads does this apply to? I have seen most heads and head setups.

I agree with that statement for A4/A5/A7 heads, but definitely not A9 (Analog Spectra). I'm not sure about changing the W9 between front and rear.

I tried two front heads on an Astro Spectra yesterday and it "mostly worked." In fact I did not notice any problem with either head. I have been using a rear W7 head as the only head on another Astro Spectra.

Analog spectras have different addresses (6 vs 5) for the rear head. A9 finds out its address from the EEPROM. There is no soldered PROM in the A9/W9; the PROM in this head is in a socket. The soldered chip in the A9/W9 is an EEPROM intended for data storage. Its contents can always be changed without desoldering it. It is very easy to change an A9 head to rear or vice versa.

There is no PROM in A4/A5/A7/W4/W5/W7 heads. The chip that stores the program is called a microcontroller.

(Old systems 9000 heads, like HCN1033, that look like A9 have the program stored in a microcontroller, which is in a socket. The EEPROM in this head is also in a socket. This one can't be used with Astro, but with the latest firmware, it works great as an A9 spectra "x9000e" head.)