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• Programmable logic

  Keith • 03/25/2022 at 16:54 • 0 comments

  I've got a bit further analysing the equations than the files uploaded on the 13th March, but for some reason I am unable to upload files as of now.

  The 68008 board PAL chips provide good hints about the logic. 

  The 68000 logic seems to be complicated by the fact the data bus interface is neither 8-bit (like the 68008) nor can it be made so by dynamic bus sizing (like the 68020).

  Instead, the logic appears to generate two 8-bit STEbus cycles for every 16-bit CPU cycle.

  One of the bytes is temporarily held in a latch (a 74ACT646) while the other passes through a buffer (a 74ACT245). These present two bus loads that are in total probably less than one LS TTL load.

• Sourcing

  Keith • 02/19/2022 at 21:52 • 0 comments

  2022-02-19

  Spotted one for $220. Bought it. Works out to be $327.22 or £240.77 after import duty and postage. Not cheap but STEbus evangelism is my bag. Due to arrive in March, when I shall read its programmables!

• About the PlasmaQuad 3

  Keith • 02/25/2021 at 13:35 • 0 comments

  According to https://core.ac.uk/reader/82231630

  The new VG PlasmaQuad 3 system is the "highest performance quadrupole ICPMS ever built, and the most automated" claims the company.  It introduces a range of new features, including a fully automated dual-mode plasma torch designed to operate in the standard mode for the majority of elemental determinations, and in a cool plasma mode for the determination of selected elements; the "S" option interface to dramatically increase sensitivity allowing routine determination of sub ppq levels; Super-Quant to automatically provide accurate, interference-corrected concentrations; and, AutoRange plus, an advanced detector system providing a linear dynamic range of eight orders of magnitude, increases accuracy and productivity.

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