Date   : Mon, 27 Feb 2006 20:13:31 -0000
From   : "Helen & John Simpson" <helenandjohn.simpson@...>
Subject: Re: BEEBUG Eprom programmer

Stephen
 
I've built the variant of this developed by Angus Duggan, and
amazingly.... I've got exactly the same problem!
 
I bought a new TL497 and put that in, to no avail. However the support
components all look OK on mine and I don't think the 1 ohm resistor gets
hot. However, I only get 0.3V on Vpp.
 
I /was/ getting the requisite 20V (although at that time I had other
problems, now fixed I think), so something has changed.
 
john

-----Original Message-----
From: Majordomo List Manager [mailto:majordomo@...] On Behalf
Of Stephen Sudworth
Sent: 26 February 2006 20:44
To: bbc-micro@...
Subject: [BBC-Micro] BEEBUG Eprom programmer


Hello there,
 
Has anyone out there built this programmer and got it to work correctly?
 
I've done the software, and made up the board, after some tinkering its
all working of a fashion (it reads eproms at least).
 
I suspect that I've blown the TL497, the 1ohm resistor has smoked and
blown (i've now replaced this with a 10ohm as i've got no 1ohm's- it
still gets VERY hot), and there is no voltage on the Vpp pin.
 
If anyone has had a go at this, i'd welcome any advice you's like to
give.
 
Thanks
 
Stephen



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